What is CVE-2026-115355?

CVE-2026-115355 is a high-severity vulnerability in Lepture Mistune, classified under Path Traversal. CVSS score: 7.5/10. Published 2026-10-22.

How severe is CVE-2026-115355?

High severity. CVSS v3 base score is 7.5 out of 10.

Path Traversal in Lepture Mistune

CVE-2026-115355

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.

Vulnerability class: Path Traversal (Directory Traversal)

Published 2026-10-22 · last modified 2026-10-22.

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N.

EPSS exploit prediction

No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.

Affected products

Lepture Mistune

Weakness classification (CWE)

CWE-22 — Path Traversal

References

github.com/lepture/mistune/security/advisories/GHSA-h7ww-273w-6cm8 (vendor-advisory)
www.vulncheck.com/advisories/mistune-before-3.3.0-path-traversal-and-xss-via-in… (third-party-advisory)

Frequently asked questions

What is CVE-2026-115355?: CVE-2026-115355 is a high-severity vulnerability in Lepture Mistune, classified under Path Traversal. CVSS score: 7.5/10. Published 2026-10-22.
How severe is CVE-2026-115355?: High severity. CVSS v3 base score is 7.5 out of 10.