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.
References8
- github.com/Cotonti/Cotonti
- github.com/Cotonti/Cotonti/blob/1.0.0/plugins/comments/comments…
- github.com/Cotonti/Cotonti/blob/1.0.0/plugins/comments/controll…
- github.com/Cotonti/Cotonti/blob/1.0.0/plugins/comments/inc/Comm…
- github.com/Cotonti/Cotonti/issues/1888
- github.com/Cotonti/Cotonti/pull/1889
- www.vulncheck.com/advisories/cotonti-1.0.0-comments-plugin-php-…
- github.com/Cotonti/Cotonti/issues/1888
Metrics
- CVSS 3.1
-
9.8
CRITICAL
Score source: CNA
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - CVSS 4.0
-
9.3
CRITICAL
Score source: CNA
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - EPSS — exploit probability
- 1% percentile: 62 · as of 7 November 2026
- CWE
- CWE-502
Could this be exploited in your environment?
A patch closes the known hole. A penetration test shows what an attacker can still reach — with proof.