CVE-2026-115353

High

Description

Mistune before 3.3.0 contains a path traversal vulnerability in the RST include directive that allows attackers to read arbitrary files by supplying relative or absolute paths. Attackers can submit markdown containing include directives referencing ../ sequences or absolute paths to embed sensitive files like credentials or environment data in rendered HTML.

SeverityHigh

CVSS8.6

Exploit probability—

ProductLepture Mistune

PublishedOct 22, 2026

First seenOct 22, 2026

Weakness typeCWE-22Path traversal

How to fix

Update

lepture mistune3.3.0 or later

Vendor advisories

github.com/lepture/mistune/security/advisories/GHSA-9jjx-3hq3-hx4j

Affected products

Product	Affected versions	Fixed in
lepture mistune	v < 3.3.0	3.3.0

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