Vulnerability-Lookup

rustsec-2026-0033

Vulnerability from osv_rustsec

Published

2026-03-04 12:00

Modified

2026-03-06 06:03

Summary

HTTP Request Smuggling via Premature Upgrade

Details

Pingora versions prior to 0.8.0 would immediately forward bytes following a request with an Upgrade header to the backend, without waiting for a 101 Switching Protocols response. This allows an attacker to smuggle requests to the backend and bypass proxy-level security controls.

This vulnerability primarily affects standalone Pingora deployments where a Pingora proxy is exposed to external traffic. An attacker could exploit this to bypass proxy-level ACL controls and WAF logic, poison caches and upstream connections, or perform cross-user attacks by hijacking sessions.

This flaw was corrected in commit 824bdeefc61e121cc8861de1b35e8e8f39026ecd by only switching connection modes after receiving a 101 response from the backend. Users should upgrade to Pingora >= 0.8.0.

Note: Cloudflare customers and Cloudflare's CDN infrastructure were not affected by this vulnerability, as ingress proxies in the CDN stack maintain proper HTTP parsing boundaries and do not prematurely switch to upgraded connection forwarding mode.

JSON

To clipboard

{
  "affected": [
    {
      "database_specific": {
        "categories": [],
        "cvss": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:H/SI:H/SA:N",
        "informational": null
      },
      "ecosystem_specific": {
        "affected_functions": null,
        "affects": {
          "arch": [],
          "functions": [],
          "os": []
        }
      },
      "package": {
        "ecosystem": "crates.io",
        "name": "pingora-core",
        "purl": "pkg:cargo/pingora-core"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0.0.0-0"
            },
            {
              "fixed": "0.8.0"
            }
          ],
          "type": "SEMVER"
        }
      ],
      "versions": []
    }
  ],
  "aliases": [
    "CVE-2026-2833",
    "GHSA-xq2h-p299-vjwv"
  ],
  "database_specific": {
    "license": "CC0-1.0"
  },
  "details": "Pingora versions prior to 0.8.0 would immediately forward bytes following a request with an Upgrade header to the backend, without waiting for a 101 Switching Protocols response. This allows an attacker to smuggle requests to the backend and bypass proxy-level security controls.\n\nThis vulnerability primarily affects standalone Pingora deployments where a Pingora proxy is exposed to external traffic. An attacker could exploit this to bypass proxy-level ACL controls and WAF logic, poison caches and upstream connections, or perform cross-user attacks by hijacking sessions.\n\nThis flaw was corrected in commit 824bdeefc61e121cc8861de1b35e8e8f39026ecd by only switching connection modes after receiving a 101 response from the backend. Users should upgrade to Pingora \u003e= 0.8.0.\n\nNote: Cloudflare customers and Cloudflare\u0027s CDN infrastructure were not affected by this vulnerability, as ingress proxies in the CDN stack maintain proper HTTP parsing boundaries and do not prematurely switch to upgraded connection forwarding mode.",
  "id": "RUSTSEC-2026-0033",
  "modified": "2026-03-06T06:03:13Z",
  "published": "2026-03-04T12:00:00Z",
  "references": [
    {
      "type": "PACKAGE",
      "url": "https://crates.io/crates/pingora-core"
    },
    {
      "type": "ADVISORY",
      "url": "https://rustsec.org/advisories/RUSTSEC-2026-0033.html"
    },
    {
      "type": "WEB",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-2833"
    }
  ],
  "related": [],
  "severity": [
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:H/SI:H/SA:N",
      "type": "CVSS_V4"
    }
  ],
  "summary": "HTTP Request Smuggling via Premature Upgrade"
}

GHSA-XQ2H-P299-VJWV

Vulnerability from github – Published: 2026-03-05 20:55 – Updated: 2026-03-05 20:55

Summary

Pingora vulnerable to HTTP Request Smuggling via Premature Upgrade

Details

Impact

Patches

Pingora users should upgrade to Pingora v0.8.0 or higher, which fixes this issue by only switching connection modes after receiving a 101 Switching Protocols response from the backend (hash 824bdeefc61e121cc8861de1b35e8e8f39026ecd). Without a 101 response, subsequent bytes continue to be parsed as HTTP requests.

Workarounds

As a workaround, users may return an error on requests with the Upgrade header present in their request filter logic in order to stop processing bytes beyond the request header and disable downstream connection reuse.

Resources

See https://www.cve.org/cverecord?id=CVE-2026-2833. An upcoming Cloudflare blog will also contain more details.

Credits

Disclosed responsibly by Rajat Raghav (@xclow3n) through the Cloudflare Bug Bounty Program.

Severity ?

9.3 (Critical)


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

Show details on source website

JSON

To clipboard

{
  "affected": [
    {
      "database_specific": {
        "last_known_affected_version_range": "\u003c= 0.7.0"
      },
      "package": {
        "ecosystem": "crates.io",
        "name": "pingora-core"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "0.8.0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-2833"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-444"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-03-05T20:55:29Z",
    "nvd_published_at": null,
    "severity": "CRITICAL"
  },
  "details": "### Impact\nPingora versions prior to 0.8.0 would immediately forward bytes following a request with an Upgrade header to the backend, without waiting for a 101 Switching Protocols response. This allows an attacker to smuggle requests to the backend and bypass proxy-level security controls.\n\nThis vulnerability primarily affects standalone Pingora deployments where a Pingora proxy is exposed to external traffic. An attacker could exploit this to bypass proxy-level ACL controls and WAF logic, poison caches and upstream connections, or perform cross-user attacks by hijacking sessions.\n\nNote: Cloudflare customers and Cloudflare\u0027s CDN infrastructure were not affected by this vulnerability, as ingress proxies in the CDN stack maintain proper HTTP parsing boundaries and do not prematurely switch to upgraded connection forwarding mode.\n\n### Patches\nPingora users should upgrade to Pingora v0.8.0 or higher, which fixes this issue by only switching connection modes after receiving a 101 Switching Protocols response from the backend (hash 824bdeefc61e121cc8861de1b35e8e8f39026ecd). Without a 101 response, subsequent bytes continue to be parsed as HTTP requests.\n\n### Workarounds\nAs a workaround, users may return an error on requests with the Upgrade header present in their request filter logic in order to stop processing bytes beyond the request header and disable downstream connection reuse.\n\n### Resources\nSee https://www.cve.org/cverecord?id=CVE-2026-2833. An upcoming Cloudflare blog will also contain more details.\n\n### Credits\nDisclosed responsibly by Rajat Raghav (@xclow3n) through the Cloudflare [Bug Bounty Program](https://www.cloudflare.com/disclosure/).",
  "id": "GHSA-xq2h-p299-vjwv",
  "modified": "2026-03-05T20:55:29Z",
  "published": "2026-03-05T20:55:29Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/cloudflare/pingora/security/advisories/GHSA-xq2h-p299-vjwv"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-2833"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/cloudflare/pingora"
    },
    {
      "type": "WEB",
      "url": "https://rustsec.org/advisories/RUSTSEC-2026-0033.html"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:H/SI:H/SA:N",
      "type": "CVSS_V4"
    }
  ],
  "summary": "Pingora vulnerable to HTTP Request Smuggling via Premature Upgrade"
}

CVE-2026-2833 (GCVE-0-2026-2833)

Vulnerability from cvelistv5 – Published: 2026-03-04 23:20 – Updated: 2026-03-06 18:26

Title

HTTP Request Smuggling via Premature Upgrade

Summary

An HTTP request smuggling vulnerability (CWE-444) was found in Pingora's handling of HTTP/1.1 connection upgrades. The issue occurs when a Pingora proxy reads a request containing an Upgrade header, causing the proxy to pass through the rest of the bytes on the connection to a backend before the backend has accepted the upgrade. An attacker can thus directly forward a malicious payload after a request with an Upgrade header to that backend in a way that may be interpreted as a subsequent request header, bypassing proxy-level security controls and enabling cross-user session hijacking. Impact This vulnerability primarily affects standalone Pingora deployments where a Pingora proxy is exposed to external traffic. An attacker could exploit this to: * Bypass proxy-level ACL controls and WAF logic * Poison caches and upstream connections, causing subsequent requests from legitimate users to receive responses intended for smuggled requests * Perform cross-user attacks by hijacking sessions or smuggling requests that appear to originate from the trusted proxy IP Cloudflare's CDN infrastructure was not affected by this vulnerability, as ingress proxies in the CDN stack maintain proper HTTP parsing boundaries and do not prematurely switch to upgraded connection forwarding mode. Mitigation: Pingora users should upgrade to Pingora v0.8.0 or higher As a workaround, users may return an error on requests with the Upgrade header present in their request filter logic in order to stop processing bytes beyond the request header and disable downstream connection reuse.

Severity ?

9.3 (Critical)


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

CWE

CWE-444 - Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling')

Assigner

cloudflare

References

URL

Tags

https://github.com/cloudflare/pingora

Impacted products

	Vendor	Product	Version
	Cloudflare	https://github.com/cloudflare/pingora	Affected: 0 , < 0.8.0 (semver)

Credits

Rajat Raghav (xclow3n)

Show details on NVD website

JSON

To clipboard

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                "role": "CISA Coordinator",
                "timestamp": "2026-03-06T18:25:53.691901Z",
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Sightings

Author	Source	Type	Date

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.

Detection rules are retrieved from Rulezet.

Action not permitted

rustsec-2026-0033

Vulnerability from osv_rustsec

GHSA-XQ2H-P299-VJWV

Impact

Patches

Workarounds

Resources

Credits

CVE-2026-2833 (GCVE-0-2026-2833)

Tags

Sightings

Nomenclature