Vulnerability 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.
CVSS Score
CRITICAL
Related Weaknesses (CWE)
References
- https://github.com/Cotonti/Cotonti
- https://github.com/Cotonti/Cotonti/blob/1.0.0/plugins/comments/comments.setup.ph
- https://github.com/Cotonti/Cotonti/blob/1.0.0/plugins/comments/controllers/actio
- https://github.com/Cotonti/Cotonti/blob/1.0.0/plugins/comments/inc/CommentsWidge
- https://github.com/Cotonti/Cotonti/issues/1888
- https://github.com/Cotonti/Cotonti/pull/1889
- https://www.vulncheck.com/advisories/cotonti-1.0.0-comments-plugin-php-object-in
- https://github.com/Cotonti/Cotonti/issues/1888
FAQ
What is CVE-2026-91939?
CVE-2026-91939 is a vulnerability with a CVSS score of 9.8 (CRITICAL). 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-co...
How severe is CVE-2026-91939?
CVE-2026-91939 has been rated CRITICAL with a CVSS base score of 9.8/10. This is considered a critical vulnerability requiring immediate attention.
Is there a patch for CVE-2026-91939?
Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.