| Name | CVE-2026-59922 |
| Description | Mistune is a Python Markdown parser with renderers and plugins. Prior to 3.3.0, a run of closed tilde, equals-sign, or caret marker pairs around a character causes quadratic work in src/mistune/plugins/formatting.py when the strikethrough, mark, or insert plugin scans for matching markers from each possible start position, allowing denial of service through CPU exhaustion. This issue is fixed in version 3.3.0. |
| 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 | 1141770 |
The table below lists information on source packages.
| Source Package | Release | Version | Status |
|---|---|---|---|
| mistune (PTS) | bullseye | 0.8.4-4 | fixed |
| bookworm | 2.0.4-1 | fixed | |
| 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 | bullseye | (not affected) | |||
| mistune | source | bookworm | (not affected) | |||
| mistune | source | (unstable) | (unfixed) | 1141770 |
[trixie] - mistune <no-dsa> (Minor issue)
[bookworm] - mistune <not-affected> (Vulnerable parser construct introduced in 3.x rewrite)
[bullseye] - mistune <not-affected> (Vulnerable parser construct introduced in 3.x rewrite)
https://github.com/lepture/mistune/security/advisories/GHSA-c8j7-8cv4-2xmq
Fixed by: https://github.com/lepture/mistune/commit/96d0f57f8fe9eeb06bb4cff521962a27d7c402e7 (v3.3.0)