CVE-2026-91939 Cotonti 1.0.0 Comments Plugin PHP Object Injection via ci Parameter
Unauthenticated attackers can achieve code execution or database manipulation via PHP object injection in the Cotonti Comments plugin.
- 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-2026-91939?
CVE-2026-91939 is a critical unsafe deserialization vulnerability in Cotonti, published on 15 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
Cotonti 1.0.0 Comments plugin passes the ci GET parameter to unserialize() without allowed_classes restriction, allowing unauthenticated attackers to instantiate arbitrary PHP classes with attacker-controlled properties. Attackers can exploit PHP object injection through crafted serialized payloads to trigger gadget chains and achieve database manipulation or code execution.
Weakness: CWE-502
Which versions are affected by CVE-2026-91939?
How do I fix CVE-2026-91939?
No fix has been published for CVE-2026-91939 yet. Limit exposure of the affected software until one is available.
Upgrade, and only deserialise data from trusted sources or with an allow-list of types. More about Unsafe deserialization.
Is CVE-2026-91939 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-91939 exists.
Sources
Also known as GHSA-xv9c-9hwm-jp8g.