PyPI/mistune CVE-2026-59928: high 7.5

Mistune block_parser: quadratic-time parsing on long lists of repeated reference-link definitions

Action: Upgrade mistune to 3.3.0 or later.

pip install mistune==3.3.0

Affected

Fixed versions

Sources

• osv: GHSA-ffq3-xpv3-j92q
• https://github.com/lepture/mistune/security/advisories/GHSA-ffq3-xpv3-j92q
• https://nvd.nist.gov/vuln/detail/CVE-2026-59928
• https://github.com/lepture/mistune/commit/2b04d7ba341c16ac78fe82d3076bdd5c3de87c69
• https://github.com/lepture/mistune
• https://github.com/lepture/mistune/releases/tag/v3.3.0
• https://github.com/pypa/advisory-database/tree/main/vulns/mistune/PYSEC-2026-2216.yaml

CVE-2026-59928 · published 2026-07-20T21:24:18Z · modified 2026-07-20T21:30:38.320453360Z · JSON