CVE-2026-17544: PHP

Critical severity, CVSS 9.8. EPSS: 0.4% chance of exploitation in the next 30 days.

Attacker-provided inputs to bccomp() could lead to an out-of-bounds write with stack and heap corruption in PHP versions from 8.4.* before 8.4.24 and from 8.5.* before 8.5.9.

Affected products

• PHP PHP: from 8.4.0, before 8.4.24 (fixed in 8.4.24); from 8.5.0, before 8.5.9 (fixed in 8.5.9)

Published 2026-07-30. Last modified 2026-08-05.