CVE-2026-46338: PyMdown Extensions is a set of extensions for the Python-Markdown markdown project

Routine

MEDIUM 4.3UPGRADE

CVE-2026-46338 is a medium-severity flaw (CVSS 4.3) affecting pymdown extensions. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

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. Thi

Why this priority

Public exploit reference

A fixed release or distro patch exists.

Risk facts

CVSS score	4.3 (Medium)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	Required
EPSS exploit chance	0.4% (top 67%)
CISA exploited list	No
Weakness	CWE-22
Published	2026-07-16
Last modified	2026-10-24

Publisher (CNA): GitHub, Inc. · Vendor: facelessuser

Last updated 2026-10-24 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-07-16 19:16 UTCPublished CVE record published
2026-10-24 20:10 UTCUpdated Record last modified

facelessuser pymdown extensions UPGRADE

Affected: >= 10.0.1 and < 10.21.3

Fixed in: 10.21.3

Safe to downgrade to: a release before 10.0.1

1. Check installed version

apt-cache policy pymdown-extensions || rpm -q pymdown-extensions || pymdown-extensions --version

2. UPGRADE to 10.21.3 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade pymdown-extensions

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade pymdown-extensions

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

3. If no update is available yet, DOWNGRADE to a release before 10.0.1 (Debian / Ubuntu)

apt-cache madison pymdown-extensions sudo apt install pymdown-extensions=<VERSION_BEFORE_10.0.1> sudo apt-mark hold pymdown-extensions

3. If no update is available yet, DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list pymdown-extensions sudo dnf downgrade pymdown-extensions-<VERSION_BEFORE_10.0.1> sudo dnf versionlock add pymdown-extensions

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-46338?

pymdown extensions: upgrade to 10.21.3. Exact commands for each OS are on this page.

Is CVE-2026-46338 being exploited?

CVE-2026-46338 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-46338 affect?

CVE-2026-46338 affects pymdown extensions. Severity is medium (CVSS 4.3). 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 `

How urgent is CVE-2026-46338?

Priority 28/100. Public exploit reference

Software pages

Python vulnerabilities

References

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