TI-2026-42732 Aliases CVE-2026-59924 GHSA-r4rv-85jg-w4mf

Mistune: Arbitrary File Read via Include directive path traversal

LOW 27CWE-22Published 2026-07-08 · Updated 2026-07-08

Key facts

Attack vector: Network
Privileges required: None
User interaction: None
Attack complexity: High
Impact type: Information disclosure
Confidentiality · integrity · availability: High · None · None
Fix status: Partial Red Hat: 3 without a fix

Attack profile from CVSS 3.1 · CNA. Fix status from CNA, GitHub and Red Hat. Impact type from CWE-22 and the CVSS impact.

Summary

Mistune is a Python Markdown parser with renderers and plugins. Prior to 3.3.0, Include.parse() joins and normalizes user-supplied include paths without verifying that the result remains within the intended markdown directory, allowing crafted include paths to access files outside that directory when markdown files are processed using md.read(). This issue is fixed in version 3.3.0.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV

EPSS 0.00462 40th percentileScored 2026-11-07

Public exploit Yes 1 exploit referenceTagged by NVD

Fix Partial mistune (lepture): 3.3.0mistune (PyPI): 3.3.0Red Hat: 3 without a fix

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation: None
Automatable: No
Technical impact: Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

Vendor	Product	Affected versions	Fixed in	Status	Source
lepture	mistune	before 3.3.0	3.3.0	Patch available	CNA
—	mistune (PyPI)	before 3.3.0	3.3.0	Patch available	GHSA-r4rv-85jg-w4mf

mistune Vendorlepture Affected before 3.3.0 Fixed in 3.3.0 Patch available CNA
mistune (PyPI) Vendor— Affected before 3.3.0 Fixed in 3.3.0 Patch available GHSA-r4rv-85jg-w4mf

CPE configurations NVD · 1

CPE	Versions	Role	Vendor
cpe:2.3:a:mistune_project:mistune::::::::	before 3.3.0	Vulnerable	lepture

cpe:2.3:a:mistune_project:mistune:*:*:*:*:*:*:*:* Versions before 3.3.0 Vulnerable ·lepture

Remediation

Fix · CNA mistune (lepture) Fixed in 3.3.0
Fix · GHSA-r4rv-85jg-w4mf mistune (PyPI) Fixed in 3.3.0 Advisory →

Vendor assessments

Red Hat

Red Hat rating: Moderate. Red Hat's page for this CVE →

Product	Status	Plan or fix
Migration Toolkit for Applications 8	Affected	No fix yet: Fix deferred
Red Hat OpenShift AI (RHOAI)	Affected	No fix yet: Fix deferred
Red Hat OpenShift Container Platform 4	Affected	No fix yet: Fix deferred

Timeline

2026-10-02 Threatist record created from CVE-2026-59924
2026-10-03 Alias added: GHSA-r4rv-85jg-w4mf

References

Other 3

TI-2026-42736 Mistune block_parser: quadratic-time parsing on long lists of repeated reference-link definitions CVSS 3.1HIGH 7.5
TI-2026-42730 Regular expression denial of service in lepture mistune CVSS 3.1HIGH 7.5
TI-2026-42731 Mistune: XSS via percent-encoded javascript URI bypass in safe_url() CVSS 3.1MEDIUM 6.1
TI-2026-32774 Mistune Image Directive CSS Injection Vulnerability CVSS 3.1MEDIUM 6.1
TI-2026-32773 Mistune TOC Anchor Injection XSS CVSS 3.1MEDIUM 6.1
TI-2026-32595 Mistune Math Plugin XSS Escape Bypass CVSS 3.1MEDIUM 6.1

See all 16 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences