CVE-2006-1991: PHP

Medium severity, CVSS 6.4. EPSS: 2.2% chance of exploitation in the next 30 days.

The substr_compare function in string.c in PHP 5.1.2 allows context-dependent attackers to cause a denial of service (memory access violation) via an out-of-bounds offset argument.

Affected products

• PHP PHP: version 5.1.2 only

Published 2006-04-24. Last modified 2026-06-16.