Vulnerability-Lookup

Vulnerability from bitnami_vulndb

Published

2026-04-13 05:43

Modified

2026-09-08 08:34

Summary

TOCTOU permits root escape on Linux via Root.Chmod in os in internal/syscall/unix

Details

On Linux, if the target of Root.Chmod is replaced with a symlink while the chmod operation is in progress, Chmod can operate on the target of the symlink, even when the target lies outside the root. The Linux fchmodat syscall silently ignores the AT_SYMLINK_NOFOLLOW flag, which Root.Chmod uses to avoid symlink traversal. Root.Chmod checks its target before acting and returns an error if the target is a symlink lying outside the root, so the impact is limited to cases where the target is replaced with a symlink between the check and operation.

JSON

To clipboard

{
  "affected": [
    {
      "package": {
        "ecosystem": "Bitnami",
        "name": "golang",
        "purl": "pkg:bitnami/golang"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.25.9"
            },
            {
              "introduced": "1.26.0-0"
            },
            {
              "fixed": "1.26.2"
            }
          ],
          "type": "SEMVER"
        }
      ],
      "severity": [
        {
          "score": "CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H",
          "type": "CVSS_V3"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-32282"
  ],
  "database_specific": {
    "cpes": [
      "cpe:2.3:a:golang:go:*:*:*:*:*:*:*:*"
    ],
    "severity": "Medium"
  },
  "details": "On Linux, if the target of Root.Chmod is replaced with a symlink while the chmod operation is in progress, Chmod can operate on the target of the symlink, even when the target lies outside the root. The Linux fchmodat syscall silently ignores the AT_SYMLINK_NOFOLLOW flag, which Root.Chmod uses to avoid symlink traversal. Root.Chmod checks its target before acting and returns an error if the target is a symlink lying outside the root, so the impact is limited to cases where the target is replaced with a symlink between the check and operation.",
  "id": "BIT-golang-2026-32282",
  "modified": "2026-09-08T08:34:36.952Z",
  "published": "2026-04-13T05:43:42.625Z",
  "references": [
    {
      "type": "FIX",
      "url": "https://go.dev/cl/763761"
    },
    {
      "type": "REPORT",
      "url": "https://go.dev/issue/78293"
    },
    {
      "type": "DISCUSSION",
      "url": "https://groups.google.com/g/golang-announce/c/0uYbvbPZRWU"
    },
    {
      "type": "WEB",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-32282"
    },
    {
      "type": "ADVISORY",
      "url": "https://pkg.go.dev/vuln/GO-2026-4864"
    }
  ],
  "schema_version": "1.6.2",
  "summary": "TOCTOU permits root escape on Linux via Root.Chmod in os in internal/syscall/unix"
}

CVE-2026-32282 (GCVE-0-2026-32282)

Vulnerability from cvelistv5 – Published: 2026-04-08 01:06 – Updated: 2026-04-13 18:20

Title

TOCTOU permits root escape on Linux via Root.Chmod in os in internal/syscall/unix

Summary

Severity

6.4 (Medium)


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

SSVC

Exploitation: none Automatable: no Technical Impact: total

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-04-13 17:47 UTC

CWE

CWE-61 - UNIX Symbolic Link (Symlink) Following

Assigner

Go Google root

References

4 references

URL	Tags
https://go.dev/cl/763761
https://go.dev/issue/78293
https://groups.google.com/g/golang-announce/c/0uY…
https://pkg.go.dev/vuln/GO-2026-4864

Impacted products

1 product

Vendor	Product	Version
Go standard library	internal/syscall/unix	Affected: 0 , < 1.25.9 (semver) Affected: 1.26.0-0 , < 1.26.2 (semver)

Credits

Uuganbayar Lkhamsuren (https://github.com/uug4na)

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "cvssV3_1": {
              "attackComplexity": "HIGH",
              "attackVector": "LOCAL",
              "availabilityImpact": "HIGH",
              "baseScore": 6.4,
              "baseSeverity": "MEDIUM",
              "confidentialityImpact": "HIGH",
              "integrityImpact": "HIGH",
              "privilegesRequired": "HIGH",
              "scope": "UNCHANGED",
              "userInteraction": "NONE",
              "vectorString": "CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H",
              "version": "3.1"
            }
          },
          {
            "other": {
              "content": {
                "id": "CVE-2026-32282",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "total"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-04-13T17:47:42.666766Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-04-13T18:20:56.456Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "collectionURL": "https://pkg.go.dev",
          "defaultStatus": "unaffected",
          "packageName": "internal/syscall/unix",
          "platforms": [
            "linux"
          ],
          "product": "internal/syscall/unix",
          "programRoutines": [
            {
              "name": "Fchmodat"
            }
          ],
          "vendor": "Go standard library",
          "versions": [
            {
              "lessThan": "1.25.9",
              "status": "affected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThan": "1.26.2",
              "status": "affected",
              "version": "1.26.0-0",
              "versionType": "semver"
            }
          ]
        }
      ],
      "credits": [
        {
          "lang": "en",
          "value": "Uuganbayar Lkhamsuren (https://github.com/uug4na)"
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "On Linux, if the target of Root.Chmod is replaced with a symlink while the chmod operation is in progress, Chmod can operate on the target of the symlink, even when the target lies outside the root. The Linux fchmodat syscall silently ignores the AT_SYMLINK_NOFOLLOW flag, which Root.Chmod uses to avoid symlink traversal. Root.Chmod checks its target before acting and returns an error if the target is a symlink lying outside the root, so the impact is limited to cases where the target is replaced with a symlink between the check and operation."
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "description": "CWE-61: UNIX Symbolic Link (Symlink) Following",
              "lang": "en"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-04-08T01:06:55.953Z",
        "orgId": "1bb62c36-49e3-4200-9d77-64a1400537cc",
        "shortName": "Go"
      },
      "references": [
        {
          "url": "https://go.dev/cl/763761"
        },
        {
          "url": "https://go.dev/issue/78293"
        },
        {
          "url": "https://groups.google.com/g/golang-announce/c/0uYbvbPZRWU"
        },
        {
          "url": "https://pkg.go.dev/vuln/GO-2026-4864"
        }
      ],
      "title": "TOCTOU permits root escape on Linux via Root.Chmod in os in internal/syscall/unix"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "1bb62c36-49e3-4200-9d77-64a1400537cc",
    "assignerShortName": "Go",
    "cveId": "CVE-2026-32282",
    "datePublished": "2026-04-08T01:06:55.953Z",
    "dateReserved": "2026-03-11T16:38:46.556Z",
    "dateUpdated": "2026-04-13T18:20:56.456Z",
    "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.

Detection rules are retrieved from Rulezet.

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

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