9.2 Critical

CVE-2026-115353 Mistune before 3.3.0 Path Traversal via include Directive

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.

CVSS 4.0 detail

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:H/SI:N/SA:N

Exploitable remotely over the network, without an account and without any user action; an attacker can seriously compromise confidentiality, integrity or availability.

Attack vector: Network
Attack complexity: Low
Attack requirements: None
Privileges required: None
Interaction: None
Confidentiality: High
Integrity: None
Availability: None
Confidentiality of other systems: High
Integrity of other systems: None
Availability of other systems: None

Affected products and versions

Product	Affected versions	Fixed in
mistune 3.3	earliest → < 3.3.0	3.3.0

References

GitHub Security Advisory (GHSA-9jjx-3hq3-hx4j) github.com
VulnCheck Advisory: Mistune before 3.3.0 Path Traversal via include Directive www.vulncheck.com

Timeline

Published October 22, 2026
Last modified November 4, 2026

The 28 CVEs of mistune →

CVE-2026-121437 Mistune from 3.3.0 before 3.3.4 contains a denial of service vulnerability that allows remote attackers to exhaust CPU… 8.7 High CVE-2026-121438 Mistune before 3.3.3 contains a denial of service vulnerability in InlineParser.parse_link that allows attackers to… 6.9 Medium CVE-2026-115355 Mistune before 3.3.0 contains a path traversal vulnerability in the Include directive that allows attackers to read… 8.7 High CVE-2026-115354 Mistune before 3.3.0 contains a path traversal vulnerability in the opt-in Include directive that allows attackers to… 7.1 High

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