CVE-2026-115353 — mistune
CVE-2026-115353 is a Path Traversal vulnerability. A fix is available — see the affected versions and patch details below.
Mistune before 3.3.0 Path Traversal via include Directive
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
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.
Detection & mitigation playbook
VulnerabilityDetect
Identify every host running the affected component and compare the installed build against the fixed version below — for source-built or distro-packaged software the version string, not a lockfile, is the source of truth (`dpkg -l`, `rpm -q`, or the binary's own `--version`).
Fix
Upgrade the affected component to the fixed release for CVE-2026-115353, or apply your distribution's backported patch — distro builds are often patched at an older version number, so check your vendor's advisory rather than the upstream version alone.
Workarounds
Resolve every user-supplied path to its canonical form and reject anything that escapes the intended directory, and run the component under an account that has no read or write access outside the directory it legitimately serves.
Frequently Asked Questions
Is CVE-2026-115353 in your dependencies?
Find it across , including transitive dependencies.