CVE-2017-12933: PHP

Critical severity, CVSS 9.8. EPSS: 6.9% chance of exploitation in the next 30 days.

The finish_nested_data function in ext/standard/var_unserializer.re in PHP before 5.6.31, 7.0.x before 7.0.21, and 7.1.x before 7.1.7 is prone to a buffer over-read while unserializing untrusted data. Exploitation of this issue can have an unspecified impact on the integrity of PHP.

Affected products

• PHP PHP: up to and including 5.6.30; version 7.0.0 only; version 7.0.1 only; version 7.0.2 only; version 7.0.3 only; version 7.0.4 only; …

Published 2017-08-18. Last modified 2026-06-17.