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python3 — security advisory

Type: advisorySources: OSVAdvisory ID: ALPINE-CVE-2026-12345

The cleanup of tempfile.TemporaryDirectory is vulnerable to a race condition. An attacker who can modify the tree during cleanup can replace a directory with a symbolic link, causing files outside of the temporary directory to be deleted or have their permissions and file flags reset, with the privileges of the process performing the cleanup. Note that platforms where shutil.rmtree.avoids_symlink_attacks is false, remain affected, and file flags may still be reset outside of the tree on all platforms.

Products
python3
Affected versions
Not specified
Fixed versions
3.14.10-r0
CVEs
CVE-2026-12345
Confirmed fixed CVEs
Not specified
Updated in this feed
1 Nov 2026, 17:42 UTC · Revision 1

Source evidence

ALPINE-CVE-2026-12345

core-osv · Original source

Published 29 Sept 2026, 18:17 UTC

The cleanup of tempfile.TemporaryDirectory is vulnerable to a race condition. An attacker who can modify the tree during cleanup can replace a directory with a symbolic link, causing files outside of the temporary directory to be deleted or have their permissions and file flags reset, with the privileges of the process performing the cleanup. Note that platforms where shutil.rmtree.avoids_symlink_attacks is false, remain affected, and file flags may still be reset outside of the tree on all platforms.

osv:ALPINE-CVE-2026-12345

python3

Fixed versions: 3.14.10-r0

Complete source record
{
  "id": "b9a3ce9dc39bff3dc6ddd400f42ace5a0911cbeb0f4eabe3fcd6513ee85378de",
  "url": "https://osv.dev/vulnerability/ALPINE-CVE-2026-12345",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "ALPINE-CVE-2026-12345",
    "summary": "The cleanup of tempfile.TemporaryDirectory is vulnerable to a race condition. An attacker who can modify the tree during cleanup can replace a directory with a symbolic link, causing files outside of the temporary directory to be deleted or have their permissions and file flags reset, with the privileges of the process performing the cleanup. Note that platforms where shutil.rmtree.avoids_symlink_attacks is false, remain affected, and file flags may still be reset outside of the tree on all platforms.",
    "evidence": "osv:ALPINE-CVE-2026-12345",
    "products": [
      {
        "name": {
          "value": "python3",
          "evidence": "/affected/0/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "3.14.10-r0",
            "evidence": "/affected/0/ranges"
          }
        ],
        "affected_versions": []
      }
    ],
    "severity": "medium",
    "structured": {
      "id": "ALPINE-CVE-2026-12345",
      "aliases": [
        "ALPINE-CVE-2026-12345"
      ],
      "metrics": [
        {
          "type": "CVSS_V4",
          "score": "CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:N/VC:N/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "3.14.10-r0"
                }
              ]
            }
          ],
          "package": {
            "name": "python3",
            "purl": "pkg:apk/alpine/python3?arch=source",
            "ecosystem": "Alpine:v3.24"
          },
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/alpine/ALPINE-CVE-2026-12345.json"
          },
          "ecosystem_specific": {}
        }
      ],
      "modified": "2026-10-27T08:30:02.298596994Z",
      "provider": "osv",
      "upstream": [
        "CVE-2026-12345"
      ],
      "references": [
        "https://security.alpinelinux.org/vuln/CVE-2026-12345"
      ]
    },
    "related_cves": [
      {
        "value": "CVE-2026-12345",
        "evidence": "/upstream"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 461030,
  "published_at": "2026-09-29T18:17:14.707+00:00"
}