Skip to content
Fencer Vulns
medium 4.3

CVE-2026-46338 json

PyMdown Extensions: Regression in pymdownx.snippets reintroduces sibling-prefix path traversal bypass despite restrict_base_path

published 2026-05-19 5 mo ago modified 2026-10-24 15 d ago also GHSA-62q4-447f-wv8h , PYSEC-2026-2999 , EUVD-2026-45003

cvss
4.3
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.4%
EPSS 0.4% chance of exploitation in 30 days, percentile 34%
public exploits
0
none known

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.

Patch / fix

  • pypi pymdown-extensions 10.21.3
  • facelessuser pymdown_extensions 10.21.3
  • pymdown-extensions Debian 14 11.0.1-1

debian advisories DEBIAN-CVE-2026-46338

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-46338 updated cvss 4.3

pymdown-extensions: PyMdown Extensions: Information disclosure via crafted Markdown snippets

  • Red Hat Developer Hub 1 rhdh/rhdh-hub-rhel9 Red Hat OpenShift Container Platform 4 openshift4/ose-olm-catalogd-rhel9 Red Hat Self-service automation portal 2 ansible-automation-platform/bootc-automation-portal-rhel9
    affected: workaround, no fix available “Ensure that untrusted Markdown content is not processed by the pymdownx.snippets extension. If the snippets feature is not required, it can be disabled in the MkDocs or Python-Markdown configuration.”
  • Red Hat Hardened Images trivy 0.72.0-0.1.hum1
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
Proof of concept is public
Automatable
no
Technical impact
partial
Assessed
3 mo ago

Exploit prediction

0.40% chance of exploitation in the next 30 days, higher than 34% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • github.com https://github.com/facelessuser/pymdown-extensions/security/advisories/GHSA-62q4-447f-wv8h referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 3.1 4.3 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N
GitHub 3.1 4.3 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N
OSV 3.1 4.3 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N

Affected packages

ecosystem package affected fixed in
pypi pymdown-extensions
>=10.0.1, <10.21.3
10.21.3

Affected products

  • facelessuser pymdown-extensions

Classification

Weakness
  • CWE-22 Improper Limitation of a Pathname to a Restricted Directory

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.