CVE-2026-86433

EUVD-2026-72391
commonmark versions from 1.5.0 before 2.8.4 contain a denial of service vulnerability in the Attributes extension where AttributesListener::findTargetAndDirection() performs quadratic-time sibling list scanning. Unauthenticated attackers can submit approximately 32 KB of repeated attribute blocks to cause parsing to take over 5 seconds, exhausting server resources.
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: 21.38%
Early Detection
Affected products identified ahead of NVD analysis through intelligence sources.
VendorProductVersionSource
thephpleaguecommonmark
1.5.0 ≤
𝑥
< 2.8.4
CNA
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Debian Releases
Debian Product
Codename
php-league-commonmark
bookworm
vulnerable
forky
2.10.0-1
fixed
sid
2.10.0-1
fixed
trixie
vulnerable