CVE-2026-86428

EUVD-2026-72386
commonmark versions from 1.5.0 before 2.10.0 contain a denial of service vulnerability in the AttributesExtension when processing distinctly-named attributes. Attackers can submit Markdown with numerous distinct attribute names to cause quadratic-time attribute merging and filtering, consuming disproportionate CPU resources and preventing legitimate requests from completing.
ProviderTypeBase ScoreAtk. VectorAtk. ComplexityPriv. RequiredVector
VulnCheckCNA
7.5 HIGH
NETWORK
LOW
NONE
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Base Score
CVSS 3.x
EPSS Score
Percentile: 20.09%
Early Detection
Affected products identified ahead of NVD analysis through intelligence sources.
VendorProductVersionSource
thephpleaguecommonmark
1.5.0 ≤
𝑥
< 2.10.0
CNA
Debian logo
Debian Releases
Debian Product
Codename
php-league-commonmark
bookworm
vulnerable
forky
2.10.0-1
fixed
sid
2.10.0-1
fixed
trixie
vulnerable
Common Weakness Enumeration
References
https://github.com/thephpleague/commonmark/security/advisories/GHSA-8rr7-cvq3-gmfh
https://www.vulncheck.com/advisories/commonmark-1.5.0-before-2.10.0-denial-of-service-via-attributes