CVE-2026-49851
7.5 ÉlevéeDescription
Mistune is a Python Markdown parser with renderers and plugins. Prior to 3.3.0, Mistune is vulnerable to a CPU exhaustion DoS due to superlinear (approximately O(n²)) behavior in parse_link_text. When parsing Markdown containing many consecutive [ characters, parse_link_text repeatedly scans the input using a regex search inside a loop. Each iteration re-scans a large portion of the remaining string, resulting in quadratic-time behavior. An attacker-controlled Markdown input can therefore trigger excessive CPU usage with a very small payload. This vulnerability is fixed in 3.3.0.
Produits concernés
Scores CVSS
| Version | Score | Source | Vecteur |
|---|---|---|---|
| 4.0 | 8.7 Élevée | security-advisories@github.com | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X |
| 3.1 | 7.5 Élevée | 0b0ca135-0b70-47e7-9f44-1890c2a1c46c | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
Faiblesses (CWE)
Références
- https://github.com/lepture/mistune/security/advisories/GHSA-qcq2-496w-v96p
- https://access.redhat.com/errata/RHSA-2026:60520
- https://access.redhat.com/security/cve/CVE-2026-49851
- https://bugzilla.redhat.com/show_bug.cgi?id=2492304
- https://github.com/lepture/mistune/security/advisories/GHSA-qcq2-496w-v96p
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-49851.json