CVE-2026-91939

CVSS 9.8 (critical) · published 2026-09-15

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

Source: NVD CVE-2026-91939

References

• https://github.com/Cotonti/Cotonti
• https://github.com/Cotonti/Cotonti/blob/1.0.0/plugins/comments/comments.setup.php
• https://github.com/Cotonti/Cotonti/blob/1.0.0/plugins/comments/controllers/actions/DisplayAction.php
• https://github.com/Cotonti/Cotonti/blob/1.0.0/plugins/comments/inc/CommentsWidget.php
• 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-injection-via-ci-parameter
• https://github.com/Cotonti/Cotonti/issues/1888

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