CVE catalog
CVE-2026-59927
Mistune is a Python Markdown parser with renderers and plugins. Prior to 3.3.0, the Include directive in src/mistune/directives/include.py detects only direct self-includes and not indirect cycles, al
- Severity
- Medium · CVSS 5.3
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L - Published
- Source
- [NVD] · [CVE record]
- EPSS
- 0.53% · Oct 25, 2026
Mistune is a Python Markdown parser with renderers and plugins. Prior to 3.3.0, the Include directive in src/mistune/directives/include.py detects only direct self-includes and not indirect cycles, allowing two markdown files that include each other to trigger unbounded recursion, raise RecursionError, and crash the rendering request. This issue is fixed in version 3.3.0.
Vulnerable and fixed packages
Distribution-reported package versions and fixes. These do not depend on matching against the OpenFactory package catalog.
| Distribution | Package | Release | Version | Status |
|---|---|---|---|---|
| Debian | mistune | sid | 3.4.0-1 | fixed |
| Debian | mistune | forky | 3.1.4-1 | vulnerable |
| Debian | mistune | trixie | 3.1.3-1 | vulnerable |
| Debian | mistune | bookworm | 2.0.4-1 | vulnerable |
| Cpe | mistune | Not reported | Not reported | vulnerable |
| Cpe | mistune | Not reported | 3.3.0 | fixed |
| Pip | mistune | Not reported | 3.3.0 | fixed |
| PyPI | mistune | Not reported | 3.3.0 | fixed |
| Cpe | mistune | Not reported | 3.3.0 | fixed |
Fixed-version evidence
| Distribution | Package | Type | Release | Fixed version | Urgency | Origin | Bugs |
|---|---|---|---|---|---|---|---|
| Debian | mistune | source | sid | 3.3.4-1 | not yet assigned | Not reported | [1141770] |
| Debian | mistune | source | forky | (unfixed) | not yet assigned | Not reported | [1141770] |
| Debian | mistune | source | trixie | (unfixed) | not yet assigned | Not reported | [1141770] |
| Debian | mistune | source | bookworm | (unfixed) | not yet assigned | Not reported | [1141770] |
| Cpe | mistune | cpe | Not reported | 3.3.0 | Not reported | Not reported | Not reported |
| Pip | mistune | pip | Not reported | 3.3.0 | Not reported | Not reported | Not reported |
| PyPI | mistune | PyPI | Not reported | 3.3.0 | Not reported | Not reported | Not reported |
| Cpe | mistune | cpe | Not reported | 3.3.0 | Not reported | NVD-CVE-2026-59927 | Not reported |
Notes
[trixie] mistune: Minor issue [bookworm] mistune: Minor issue
OpenFactory catalog packages
[Debian 12 (Bookworm)]
- [python3-mistune]Affected
Source package: [mistune]
Details (2)
2.0.4-1· all · bookwormAffected
nvd · mistune · debian · bookworm; nvd · mistune · debian · 12
2.0.4-1· all · bookwormAffected
nvd · mistune · debian · bookworm; nvd · mistune · debian · 12
[Debian 13 (Trixie)]
- [python3-mistune]Affected
Source package: [mistune]
Details (2)
3.1.3-1· all · trixieAffected
nvd · mistune · debian · 13
3.1.3-1· all · trixieAffected
nvd · mistune · debian · 13
Observed:
References
- [https://ftp.suse.com/pub/projects/security/csaf/suse-su-2026_22655-1.json]
- [https://github.com/advisories/GHSA-8mpj-m6qm-5qr8]
- [https://github.com/lepture/mistune/commit/1bef343ade163fc3bb95572b15be720084cdb993]
- [https://github.com/lepture/mistune/releases/tag/v3.3.0]
- [https://github.com/lepture/mistune/security/advisories/GHSA-8mpj-m6qm-5qr8]
- [https://nvd.nist.gov/vuln/detail/CVE-2026-59927]
- [https://osv.dev/vulnerability/DEBIAN-CVE-2026-59927]
- [https://osv.dev/vulnerability/GHSA-8mpj-m6qm-5qr8]
- [https://osv.dev/vulnerability/PYSEC-2026-2215]
- [https://security-tracker.debian.org/tracker/CVE-2026-59927]
- [https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-59927.json]
[Debian Security Tracker] · [FIRST EPSS] · [GitHub Advisory Database] · [National Vulnerability Database (NVD)] · [OSV Package Vulnerability Database] · [Red Hat security advisories and VEX] · [SUSE security advisories and VEX]