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OpenAdvisories
High · 7.5 CVE-2026-115355 EUVD-2026-108425GHSA-8cqv-vvq2-6p8cGHSA-h7ww-273w-6cm8

Mistune before 3.3.0 Path Traversal and XSS via Include Directive

Published Oct 22, 2026 · Updated Oct 29, 2026 · Assigned by VulnCheck

Description

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.

Affected products

VendorProductAffectedFixed
lepture mistune < 3.3.0 3.3.0

Fixed in Linux distributions

Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.

ReleasePackageFixed inAdvisory
Debian 14 mistune No fix yet —
Debian 13 mistune No fix yet —
Debian 12 mistune No fix yet —
ReleasePackageFixed inAdvisory
Ubuntu 26.10 mistune No fix yet —
Ubuntu 26.04 LTS mistune No fix yet —
Ubuntu 24.04 LTS mistune No fix yet —
Ubuntu 22.04 LTS mistune No fix yet —
Ubuntu 20.04 LTS mistune No fix yet —
Show 2 more (older releases, extended support, other products)
ReleasePackageFixed inAdvisory
Ubuntu 18.04 LTS mistune No fix yet —
Ubuntu 16.04 LTS mistune No fix yet —

Affected packages

EcosystemPackageAffectedFixedRecord
PyPI mistune < 3.3.0 3.3.0 GHSA-h7ww-273w-6cm8

References