Mistune before 3.3.0 contains a path traversal vulnerability in the RST include directive that allows attackers to
Affects mistuneSource GCVE Database
Not known to be exploited · CVSS 9.2 Critical · fixed in 3.3.0 : patch mistune as a priority.
Data as of 28 Oct 2026, 23:11 UTC
- Patch
- Available – fixed in 3.3.0
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:H/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.
AI-suggested
A fix is available in Mistune version 3.3.0 and later. Users should upgrade to version 3.3.0 or newer to remediate this vulnerability. Until upgrading, avoid processing untrusted markdown content with the vulnerable include directive.
Description
Mistune versions before 3.3.0 have a path traversal vulnerability in the RST include directive. This flaw allows attackers to craft markdown with include directives that reference relative or absolute paths, enabling them to read arbitrary files. Sensitive files such as credentials or environment data can be exposed in the rendered HTML output. The vulnerability has a high severity with a CVSS score of 8.6.
References
- ubuntu.com/security/CVE-2026-115353 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-115353 (opens in a new tab)
- github.com/lepture/mistune/security/advisories/GHSA-9jjx-3hq3-hx4j (opens in a new tab)
- vulncheck.com/advisories/mistune-before-3.3.0-path-traversal-via-include-directive (opens in a new tab)