pymdown-extensions — security advisory

{
  "id": "c96f77b7d4e4d8a684c870a411895b52efa16b093beb2996ff5cc063a80aa1e9",
  "url": "https://osv.dev/vulnerability/UBUNTU-CVE-2026-46338",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "UBUNTU-CVE-2026-46338",
    "summary": "PyMdown Extensions is a set of extensions for the Python-Markdown markdown project. From 10.0.1 until 10.21.3, pymdownx.snippets uses a string-prefix containment check in SnippetPreprocessor.get_snippet_path() in pymdownx/snippets.py when `restrict_base_path: True`, allowing markdown snippet directives to read files from sibling paths that share the same base_path prefix, such as docs and docs_internal. This is a regression of CVE-2023-32309. This issue is fixed in version 10.21.3.",
    "evidence": "osv:UBUNTU-CVE-2026-46338",
    "products": [
      {
        "name": {
          "value": "pymdown-extensions",
          "evidence": "/affected/0/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [],
        "affected_versions": [
          {
            "value": "9.5-2",
            "evidence": "/affected/0/versions"
          },
          {
            "value": "9.5-4",
            "evidence": "/affected/0/versions"
          },
          {
            "value": "9.5-5",
            "evidence": "/affected/0/versions"
          }
        ]
      },
      {
        "name": {
          "value": "pymdown-extensions",
          "evidence": "/affected/1/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [],
        "affected_versions": [
          {
            "value": "10.19.1-3",
            "evidence": "/affected/1/versions"
          },
          {
            "value": "11.0.1-1",
            "evidence": "/affected/1/versions"
          }
        ]
      },
      {
        "name": {
          "value": "pymdown-extensions",
          "evidence": "/affected/2/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [],
        "affected_versions": [
          {
            "value": "10.13-3",
            "evidence": "/affected/2/versions"
          },
          {
            "value": "10.13-4",
            "evidence": "/affected/2/versions"
          },
          {
            "value": "10.19.1-3",
            "evidence": "/affected/2/versions"
          }
        ]
      }
    ],
    "severity": "medium",
    "structured": {
      "id": "UBUNTU-CVE-2026-46338",
      "aliases": [
        "UBUNTU-CVE-2026-46338"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N"
        },
        {
          "type": "Ubuntu",
          "score": "medium"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "0"
                }
              ]
            }
          ],
          "package": {
            "name": "pymdown-extensions",
            "purl": "pkg:deb/ubuntu/pymdown-extensions?arch=source&distro=noble",
            "ecosystem": "Ubuntu:24.04:LTS"
          },
          "versions": [
            "9.5-2",
            "9.5-4",
            "9.5-5"
          ],
          "database_specific": {
            "source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-46338.json"
          },
          "ecosystem_specific": {
            "binaries": [
              {
                "binary_name": "python3-pymdownx",
                "binary_version": "9.5-5"
              }
            ]
          }
        },
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "0"
                }
              ]
            }
          ],
          "package": {
            "name": "pymdown-extensions",
            "purl": "pkg:deb/ubuntu/pymdown-extensions?arch=source&distro=stonking",
            "ecosystem": "Ubuntu:26.10"
          },
          "versions": [
            "10.19.1-3",
            "11.0.1-1"
          ],
          "database_specific": {
            "source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-46338.json"
          },
          "ecosystem_specific": {
            "binaries": [
              {
                "binary_name": "python3-pymdownx",
                "binary_version": "11.0.1-1"
              }
            ]
          }
        },
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "0"
                }
              ]
            }
          ],
          "package": {
            "name": "pymdown-extensions",
            "purl": "pkg:deb/ubuntu/pymdown-extensions?arch=source&distro=resolute",
            "ecosystem": "Ubuntu:26.04:LTS"
          },
          "versions": [
            "10.13-3",
            "10.13-4",
            "10.19.1-3"
          ],
          "database_specific": {
            "source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-46338.json"
          },
          "ecosystem_specific": {
            "binaries": [
              {
                "binary_name": "python3-pymdownx",
                "binary_version": "10.19.1-3"
              }
            ]
          }
        }
      ],
      "modified": "2026-10-17T12:55:37.580629718Z",
      "provider": "osv",
      "upstream": [
        "CVE-2026-46338"
      ],
      "references": [
        "https://ubuntu.com/security/CVE-2026-46338",
        "https://www.cve.org/CVERecord?id=CVE-2026-46338",
        "https://github.com/facelessuser/pymdown-extensions/commit/63b7835776d703d6c339cf2110d9888f676efc0c",
        "https://github.com/facelessuser/pymdown-extensions/releases/tag/10.21.3",
        "https://github.com/facelessuser/pymdown-extensions/security/advisories/GHSA-62q4-447f-wv8h"
      ]
    },
    "related_cves": [
      {
        "value": "CVE-2026-46338",
        "evidence": "/upstream"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 353913,
  "published_at": "2026-07-16T19:16:00+00:00"
}