CVE-2026-13342: Unknown Security Optimizer

Medium severity, CVSS 5.3. EPSS: 0.3% chance of exploitation in the next 30 days.

The Security Optimizer WordPress plugin from 1.5.8 to 1.6.4 does not correctly validate requests to its optional IP-based login restriction feature, allowing the restriction to be bypassed so that unauthenticated requests from non-allowlisted IP addresses can reach and use the login form, defeating the access control the administrator configured.

Affected products

• Unknown Security Optimizer: from 1.5.8, before 1.6.5 (fixed in 1.6.5)

Published 2026-08-06. Last modified 2026-08-26.