CVE-2026-86435

php-league-commonmark: commonmark versions from 1.5.0 before 2.8.4 contain a denial of service vulnerability in the Footnote extension that...

CVE-2026-86435 is fixed in php-league-commonmark on 1 platform by DEBIAN-CVE-2026-86435 (version 2.9.0-1), released September 8, 2026. It is not reported as exploited. Patch Radar priority: Routine.

Routine

CVSS

n/a

No vendor severity

Exploitation

None reported

No vendor assessment

CISA KEV

Not listed

Not in the Known Exploited Vulnerabilities catalog

EPSS

0.0049

42nd percentile

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.

Where it's fixed

Product	Fixed in	Fix	Released
Linux
php-league-commonmark · Debian 14	2.9.0-1	DEBIAN-CVE-2026-86435	Sep 8, 2026

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