CVE-2026-86435

EUVD-2026-72393
commonmark versions from 1.5.0 before 2.8.4 contain a denial of service vulnerability in the Footnote extension that fails to deduplicate footnote definitions. Attackers can craft documents with duplicate footnote definitions and references to create quadratic output expansion, consuming excessive memory and CPU to exhaust 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: 20.09%
Early Detection
Affected products identified ahead of NVD analysis through intelligence sources.
VendorProductVersionSource
thephpleaguecommonmark
1.5.0 ≤
𝑥
< 2.8.4
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-jfm3-95jq-q3rf
https://www.vulncheck.com/advisories/commonmark-1.5.0-before-2.8.4-denial-of-service-via-footnote