CVE-2026-7258: PHP

High severity, CVSS 7.5. EPSS: 0.4% chance of exploitation in the next 30 days.

In PHP versions 8.2.* before 8.2.31, 8.3.* before 8.3.31, 8.4.* before 8.4.21, and 8.5.* before 8.5.6, some functions, including urldecode(), pass signed char to ctype functions (like isxdigit()). On the systems with default signed char and optimized table-lookup ctype functions - such as NetBSD - this can lead to accessing array with negative offset, which can trigger a denial of service.

Affected products

• PHP PHP: from 8.2.0, before 8.2.21 (fixed in 8.2.21); from 8.3.0, before 8.3.31 (fixed in 8.3.31); from 8.4.0, before 8.4.21 (fixed in 8.4.21); from 8.5.0, before 8.5.6 (fixed in 8.5.6)

Published 2026-05-10. Last modified 2026-07-24.