What’s Vulnerable › Vulnerabilities
CVE-2026-88798: Really Simple Security (Free) < 9.8.3 - Unauthenticated Unbounded Option Growth via Spoofed Client IP Header
- Severity: medium (CVSS 5.3 v3.1)
- Exploited in the wild: not listed in CISA KEV
- EPSS: 0.4% probability of exploitation in the next 30 days
- Public exploit or detection template: none known
- Published: 2026-09-18 · updated 2026-09-18
- Weakness: CWE-400
Description
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
- Really Simple Security: from 8.1.6 before 9.8.3 — fixed in 9.8.3
How to fix
Upgrade to a fixed version: Really Simple Security 9.8.3. Check the vendor advisory for mitigations.
References
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