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TI-2026-79442 Aliases CVE-2026-115355GHSA-8cqv-vvq2-6p8cGHSA-h7ww-273w-6cm8

Path traversal and XSS in Mistune Include directive

Priority MEDIUM 44CWE-22Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Attack requirements
None
Impact type
Information disclosure
Confidentiality · integrity · availability
High · None · None
Fix status
Partial Red Hat: 1 without a fix

Attack profile from CVSS 4.0 · CNA. Fix status from CNA, GitHub and Red Hat. Impact type from CWE-22 and the CVSS impact.

Summary

Mistune from 0 before 3.3.0 contains a path traversal flaw in its Include directive (CWE-22). Supplying ../ sequences in include paths lets an unauthenticated remote attacker read arbitrary files. Unescaped error messages and included file contents also allow cross-site scripting even when escape=True is set.

Written with Claude Haiku 5.5 from the sources below · 2026-11-03

Description from the CNA

Mistune before 3.3.0 contains a path traversal vulnerability in the Include directive that allows attackers to read arbitrary files by supplying ../ sequences in include paths. Attackers can also inject HTML through unescaped error messages and included file contents to perform cross-site scripting even when escape=True is set.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00461 40th percentileScored 2026-11-07
Fix Partial mistune (lepture): 3.3.0mistune (PyPI): 3.3.0Red Hat: 1 without a fix

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
Yes
Technical impact
Partial

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

Affected products

VendorProductAffected versionsFixed inStatusSource
lepturemistunebefore 3.3.03.3.0Patch availableCNA
—mistune (PyPI)before 3.3.03.3.0Patch availableGHSA-h7ww-273w-6cm8
  • 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-h7ww-273w-6cm8

CPE names Threatist (inferred) · 1

Inferred from how NVD named this product before; not given by a source.

CPEVersionsRoleVendor
cpe:2.3:a:mistune_project:mistune:*:*:*:*:*:*:*:*——lepture
  • cpe:2.3:a:mistune_project:mistune:*:*:*:*:*:*:*:* Versions — — ·lepture

Remediation

Upgrade mistune to version 3.3.0, which is listed as the fixed version for both the lepture and PyPI entries. Red Hat OpenShift AI (RHOAI) is listed as affected without a fix, and Red Hat has no plan available for it.

Written with Claude Haiku 5.5 from the sources below · 2026-11-03

  • Fix · CNA mistune (lepture) Fixed in 3.3.0
  • Fix · GHSA-h7ww-273w-6cm8 mistune (PyPI) Fixed in 3.3.0 Advisory →

Fixed in the same release

Records fixed by the same vendor advisory or release, as the CNA lists them.

  • Release ·

    lepture mistune 3.3.0

    9 records Highest priority Priority HIGH 1 HIGH, 7 MEDIUM, 1 LOW

    Other records, highest priority first

    • TI-2026-79440 Path traversal in Mistune include directive lets attackers read filesPriority HIGH 79
    • TI-2026-79441 Path traversal in Mistune lets attackers read local filesPriority MEDIUM 64
    • TI-2026-79438 CSS injection in Mistune figure directive figwidth optionPriority MEDIUM 57
    Show all 9 records →

Vendor assessments

Red Hat

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

ProductStatusPlan or fix
Red Hat OpenShift AI (RHOAI)AffectedNo fix yet
Not affected: 2 products
  • Red Hat OpenShift AI (RHOAI)
  • Red Hat OpenShift Container Platform 4

Timeline

  1. 2026-10-22 Threatist record created from CVE-2026-115355
  2. 2026-10-22 Alias added: GHSA-8cqv-vvq2-6p8c
  3. 2026-10-23 Affected versions changed · Red Hat
  4. 2026-10-23 CVSS score added · Red Hat
  5. 2026-10-23 Priority changed: MEDIUM → LOW
  6. 2026-10-23 Alias added: GHSA-h7ww-273w-6cm8
  7. 2026-10-23 Fix available: PyPI/[email protected] · GHSA-h7ww-273w-6cm8
  8. 2026-10-23 Weakness changed · GHSA-h7ww-273w-6cm8
  9. 2026-10-23 5 new references · GHSA-h7ww-273w-6cm8
  10. 2026-10-29 CISA SSVC decision points changed
  11. 2026-10-29 Priority changed: LOW → MEDIUM
  12. 2026-11-03 Affected versions changed · Red Hat

References

Advisory 2

Other 3

  • TI-2026-79440 Path traversal in Mistune include directive lets attackers read files CVSS 4.0CRITICAL 9.2
  • TI-2026-36755 Mistune: Potential DoS via quadratic-time parsing in parse_link_text CVSS 4.0HIGH 8.7
  • TI-2026-25521 Mistune ReDoS in LINK_TITLE_RE allows denial of service with crafted Markdown titles CVSS 4.0HIGH 8.7
  • TI-2026-53257 Mistune has Denial of Service — RecursionError via Excessive Emphasis Markers in Markdown CVSS 3.1HIGH 7.5
  • 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
See all 30 →

Sources

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