CVE-2026-88798 Really Simple Security (Free) < 9.8.3 - Unauthenticated Unbounded Option Growth via Spoofed Client IP Header
Unauthenticated attackers can cause denial of service by spoofing client IP headers to unboundedly grow a WordPress plugin option.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-88798?
CVE-2026-88798 is a medium-severity denial of service vulnerability in Unknown Really Simple Security, published on 18 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official 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.
Weakness: CWE-400
Which versions are affected by CVE-2026-88798?
How do I fix CVE-2026-88798?
No fix has been published for CVE-2026-88798 yet. Limit exposure of the affected software until one is available.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2026-88798 being exploited?
There is no known exploitation of CVE-2026-88798 in the wild and no public exploit code.
Sources
Also known as GHSA-43h4-q789-j3pr.