CVE-2026-115355 Mistune before 3.3.0 Path Traversal and XSS via Include Directive
- Exploited in the wild
- Not known
- Fix
- Available
What is CVE-2026-115355?
CVE-2026-115355 is a high-severity vulnerability in lepture mistune, published on 22 Oct 2026.
Official 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.
Weakness: CWE-22
Which versions are affected by CVE-2026-115355?
2 open source packages ship an affected version, including mistune.
| Package | Affected | Fixed in |
|---|---|---|
mistune PyPI | All versions | 3.3.0 |
mistune PyPI | All versions | 3.3.0 |
How do I fix CVE-2026-115355?
Upgrade mistune to 3.3.0 or later.
Is CVE-2026-115355 being exploited?
There is no known exploitation of CVE-2026-115355 in the wild and no public exploit code.
Sources
Also known as DEBIAN-CVE-2026-115355, ECHO-fbfa-3d9a-c5b2, GHSA-h7ww-273w-6cm8, UBUNTU-CVE-2026-115355.