| Name | CVE-2026-44897 |
| Description | Mistune is a Python Markdown parser with renderers and plugins. Prior to 3.2.1, HTMLRenderer.heading() builds the opening <hN> tag by string-concatenating the id attribute value directly into the HTML — with no call to escape(), safe_entity(), or any other sanitisation function. A double-quote character " in the id value terminates the attribute, allowing an attacker to inject arbitrary additional attributes (event handlers, src=, href=, etc.) into the heading element. This vulnerability is fixed in 3.2.1. |
| Source | CVE (at NVD; CERT, ENISA, LWN, oss-sec, fulldisc, Debian ELTS, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more) |
| Debian Bugs | 1138260 |
The table below lists information on source packages.
| Source Package | Release | Version | Status |
|---|---|---|---|
| mistune (PTS) | bullseye | 0.8.4-4 | vulnerable |
| bookworm | 2.0.4-1 | vulnerable | |
| trixie | 3.1.3-1 | vulnerable | |
| forky, sid | 3.1.4-1 | vulnerable |
The information below is based on the following data on fixed versions.
| Package | Type | Release | Fixed Version | Urgency | Origin | Debian Bugs |
|---|---|---|---|---|---|---|
| mistune | source | (unstable) | (unfixed) | 1138260 |
[trixie] - mistune <no-dsa> (Minor issue)
[bookworm] - mistune <no-dsa> (Minor issue)
[bullseye] - mistune <no-dsa> (Minor issue)
https://github.com/lepture/mistune/security/advisories/GHSA-v87v-83h2-53w7