acl < 2.4.0 TOCTOU Symlink Traversal via getfacl/setfacl/chacl

{
  "id": "1d8838e1925f8d4f64b035fc93e172f450f62c1b5b1ae1813dd0da0a8176b4f2",
  "url": "https://osv.dev/vulnerability/CVE-2026-54370",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "acl < 2.4.0 TOCTOU Symlink Traversal via getfacl/setfacl/chacl",
    "summary": "acl before version 2.4.0 contains a time-of-check to time-of-use (TOCTOU) race condition vulnerability that allows local attackers to escalate privileges by replacing a pathname component with a symbolic link between an lstat() check and subsequent symlink-following operations such as stat(), chown(), chmod(), acl_get_file(), and acl_set_file(). Attackers who control a pathname component can redirect file access control list operations to arbitrary files when getfacl, setfacl, or chacl is invoked by a privileged process over an attacker-controlled path, resulting in local privilege escalation.",
    "evidence": "osv:CVE-2026-54370",
    "products": [],
    "severity": "high",
    "structured": {
      "id": "CVE-2026-54370",
      "aliases": [
        "CVE-2026-54370"
      ],
      "metrics": [
        {
          "type": "CVSS_V4",
          "score": "CVSS:4.0/AV:L/AC:H/AT:N/PR:L/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://cgit.git.savannah.nongnu.org/cgit/acl.git",
              "type": "GIT",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "3589787cd589b34bdd9265936e17190b6d3f17d1"
                },
                {
                  "fixed": "24a227d0ab8576612194f8a56c2314389adc74a5"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "range": [
                      {
                        "fixed": "3589787cd589b34bdd9265936e17190b6d3f17d1"
                      }
                    ],
                    "source": "REFERENCES_COMMIT"
                  },
                  {
                    "range": [
                      {
                        "fixed": "24a227d0ab8576612194f8a56c2314389adc74a5"
                      }
                    ],
                    "source": "REFERENCES_COMMIT"
                  }
                ]
              }
            }
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-54370.json"
          }
        }
      ],
      "modified": "2026-10-31T10:31:00.496774607Z",
      "provider": "osv",
      "references": [
        "https://savannah.nongnu.org/projects/acl/",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/54xxx/CVE-2026-54370.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-54370",
        "https://www.vulncheck.com/advisories/acl-toctou-symlink-traversal-via-getfacl-setfacl-chacl",
        "https://cgit.git.savannah.nongnu.org/cgit/acl.git/commit/?id=24a227d0ab8576612194f8a56c2314389adc74a5",
        "https://cgit.git.savannah.nongnu.org/cgit/acl.git/commit/?id=3589787cd589b34bdd9265936e17190b6d3f17d1"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-367"
        ],
        "cna_assigner": "VulnCheck",
        "unresolved_ranges": [
          {
            "extracted_events": [
              {
                "range": [
                  {
                    "fixed": "2.4.0"
                  }
                ],
                "source": "AFFECTED_FIELD",
                "strategy": "StandardRange"
              }
            ]
          },
          {
            "extracted_events": [
              {
                "range": [
                  {
                    "fixed": "2.4.0"
                  }
                ],
                "source": "CPE_FIELD",
                "strategy": "CPEApplicability"
              }
            ]
          },
          {
            "extracted_events": [
              {
                "range": [
                  {
                    "fixed": "2.4.0"
                  }
                ],
                "source": "DESCRIPTION"
              }
            ]
          }
        ],
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/54xxx/CVE-2026-54370.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-54370",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 460114,
  "published_at": "2026-06-29T12:38:11.63+00:00"
}