Path Traversal in Lepture Mistune
CVE-2026-115354
Mistune before 3.3.0 contains a path traversal vulnerability in the opt-in Include directive that allows attackers to read local files by supplying relative or absolute include paths. Attackers who submit Markdown rendered via Markdown.read() can disclose files such as /etc/passwd and inject unescaped HTML or script content into rendered output.
Vulnerability class: Path Traversal (Directory Traversal)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/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
Weakness classification (CWE)
References
- github.com/lepture/mistune/security/advisories/GHSA-jhcm-5rpf-j3wv (vendor-advisory)
- www.vulncheck.com/advisories/mistune-before-3.3.0-arbitrary-local-file-read-via… (third-party-advisory)
Frequently asked questions
- What is CVE-2026-115354?
- CVE-2026-115354 is a medium-severity vulnerability in Lepture Mistune, classified under Path Traversal. CVSS score: 6.5/10. Published 2026-10-22.
- How severe is CVE-2026-115354?
- Medium severity. CVSS v3 base score is 6.5 out of 10.