{
  "cveId": "CVE-2026-82331",
  "url": "https://patchblox.com/security/cve/CVE-2026-82331",
  "summary": "CVE-2026-82331 is fixed in buildstream on 1 platform, first by DEBIAN-CVE-2026-82331, released September 26, 2026. It is not reported as exploited. Patch Radar priority: Urgent.",
  "title": "buildstream: Improper link resolution before file access (\u0027link following\u0027) vulnerability in the \u0060tar\u0060 source plugin of Apache Bui...",
  "description": "Improper link resolution before file access (\u0027link following\u0027) vulnerability in the \u0060tar\u0060 source plugin of Apache BuildStream running on Python \u003C 3.12 allows malicious source tarballs to write files on the host, with the privileges of the user running BuildStream, via symlinks as part of source fetching. The impact of this issue is mitigated by:  * BuildStream projects should only use trusted sources in their elements as otherwise the build output can also not be trusted * Tracking a source tarball pins its SHA256 hash, which prevents MITM attacks of users that are fetching an already tracked project * When running on Python \u003E= 3.12, BuildStream \u003E= 2.3.0 already makes use of the Python \u0060tarfile\u0060 filter functionality, which blocks the symlink escape  Users are recommended to upgrade to version 2.8.1, which fixes this issue.",
  "published": "2026-09-23T07:16:46Z",
  "severity": "critical",
  "cvss": 9.8,
  "cvssVector": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
  "epss": 0.00408,
  "epssPercentile": 0.35381,
  "priority": "Urgent",
  "priorityTier": 2,
  "exploited": false,
  "vendorExploited": false,
  "disclosed": false,
  "fixes": [
    {
      "platform": "linux",
      "product": "buildstream",
      "release": "Debian 13.5 (trixie)",
      "fixedVersion": "1.6.9-2\u002Bdeb13u1",
      "fix": "DEBIAN-CVE-2026-82331",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2026-82331",
      "released": "2026-09-26T19:52:05Z"
    },
    {
      "platform": "linux",
      "product": "buildstream",
      "release": "Debian 14",
      "fixedVersion": "2.8.1-1",
      "fix": "DEBIAN-CVE-2026-82331",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2026-82331",
      "released": "2026-09-26T19:52:05Z"
    }
  ],
  "noFixYet": [],
  "dataAsOf": "2026-11-09T19:38:12Z",
  "attribution": {
    "text": "Data: Patchblox Patch Radar",
    "url": "https://patchblox.com/security/patch-radar",
    "terms": "https://patchblox.com/security/patch-radar/use-the-data"
  }
}