Path Traversal in pymdown-extensions (CVE-2026-46338)
Summary
Path traversal in pymdown-extensions (CVE-2026-46338). Risk of unauthorized operations or information disclosure. Exploitable via pymdownx.snippets. Mitigation: upgrade to 10.21.3 or later.
Original description
The description as published by the source.
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.
Source: GitHub Security Advisories (Global) NVD GitHub Advisory
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2026-46338 has been found in pymdown-extensions.
Attackers can target a specific entry point like pymdownx.snippets over the network to misuse the product.
Risk of unauthorized operations or information disclosure. CVSS score: 4.3/10.
What to do: upgrade pymdown-extensions to 10.21.3 or later.
If unsure, ask your IT team or search "pymdown-extensions CVE-2026-46338" on the vendor's site.
CVE-2026-46338 (pymdown-extensions) — CWE-22 / CVSS v3 4.3
Attack vector: remote (network-reachable) / unauthenticated
Attack surface: pymdownx.snippets / base_path / docs / docs_internal
Patched: 10.21.3 — apply immediately
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
Path traversal (CWE-22) exists in pymdown-extensions. Attackers reach the vulnerable code path via pymdownx.snippets without authentication.
Check the vendor advisory for the affected versions of pymdown-extensions. Attack surface: pymdownx.snippets / base_path / docs / docs_internal.
Severity: Medium (CVSS 4.3/10). Risk of unauthorized operations or information disclosure.
Update to 10.21.3.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r 'pymdown-extensions' . against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
-
1Identify exposure identify
grep -r 'pymdown-extensions' . | grep -v node_modulesリポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で
pymdown-extensionsを grep し、稼働しているサービス・バージョンを把握する。 -
2Apply patch patch
Upgrade pymdown-extensions to 10.21.3ステージング環境で 10.21.3 に上げて回帰テスト → 本番反映。回帰テストはアプリの主要ハッピーパスを含めること。
-
3Post-deployment verification verify
Confirm patched version is live in productionパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。
Affected packages
Fix status by distribution
Fixed packages published by each distribution for this CVE
- Debian DEBIAN-CVE-2026-46338 pymdown-extensions
- Ubuntu UBUNTU-CVE-2026-46338 pymdown-extensions
References
- advisory github.com
- advisory github.com
- advisory nvd.nist.gov
- package github.com
- patch github.com
- web github.com
- web github.com
- web github.com