CVE-2026-88798: Unknown Really Simple Security

Medium severity, CVSS 5.3. EPSS: 0.4% chance of exploitation in the next 30 days.

The Really Simple Security WordPress plugin before 9.8.3 does not validate a client-supplied address value before using it as a storage key in one of its own options, allowing unauthenticated attackers to grow that option without bound and to slow the site's handling of missing pages.

Affected products

• Unknown Really Simple Security: from 8.1.6, before 9.8.3 (fixed in 9.8.3)

Published 2026-09-18. Last modified 2026-09-18.