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
Affects mistuneSource GCVE Database
Not known to be exploited · CVSS 7.1 High.
Data as of 28 Oct 2026, 22:31 UTC
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:N/VA:N/SC:N/SI:N/SA:NExploitation evidence
Disclosed: evidence found.
CVE published 22 Oct 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 26.10mistunepkg:deb/ubuntu/mistune?arch=source&distro=stonkingOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSmistunepkg:deb/ubuntu/mistune?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 24.04 LTSmistunepkg:deb/ubuntu/mistune?arch=source&distro=nobleOther threats | Affected
| Fixed in– |
Ubuntu 22.04 LTSmistunepkg:deb/ubuntu/mistune?arch=source&distro=jammyOther threats | Affected
| Fixed in– |
Ubuntu 20.04 LTSmistunepkg:deb/ubuntu/mistune?arch=source&distro=focalOther threats | Affected
| Fixed in– |
Ubuntu 18.04 LTSmistunepkg:deb/ubuntu/mistune?arch=source&distro=bionicOther threats | Affected
| Fixed in– |
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
Description
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.
References
- ubuntu.com/security/CVE-2026-115354 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-115354 (opens in a new tab)
- github.com/lepture/mistune/security/advisories/GHSA-jhcm-5rpf-j3wv (opens in a new tab)
- vulncheck.com/advisories/mistune-before-3.3.0-arbitrary-local-file-read-via-include-directive (opens in a new tab)