Prior to 3.2.1, the mistune math plugin renders inline math ($...$) and block math ($$...$$) by concatenating the raw
Affects mistuneSource GCVE Database
Not known to be exploited · CVSS 6.1 Medium · fixed in 3.2.1 : update mistune when convenient.
Data as of 9 Nov 2026, 14:18 UTC
- Patch
- Available – fixed in 3.2.1
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:NExploitation evidence
Disclosed: evidence found.
CVE published 26 May 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: 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 9 Nov 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 26.10mistune0pkg:deb/ubuntu/mistune0?arch=source&distro=stonkingOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSmistunepkg:deb/ubuntu/mistune?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 25.10mistunepkg:deb/ubuntu/mistune?arch=source&distro=questingOther threats | Affected
| Fixed in– |
Ubuntu 25.10mistune0pkg:deb/ubuntu/mistune0?arch=source&distro=questingOther threats | Affected
| Fixed in– |
Ubuntu 24.04 LTSmistunepkg:deb/ubuntu/mistune?arch=source&distro=nobleOther 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
Upgrade mistune to version 3.2.1 or later, where this vulnerability is fixed. Versions prior to 3.2.1 are affected. No other mitigation is indicated or required as the fix addresses the root cause by properly escaping user input in the math plugin.
Description
Mistune is a Python Markdown parser whose math plugin, prior to version 3.2.1, improperly renders inline and block math expressions by directly concatenating raw user input into HTML output without escaping. This occurs even when escape mode is enabled, potentially allowing injection of malicious HTML or scripts. The vulnerability is fixed in version 3.2.1.