EUVD Vulnerability Catalog
EUVD-2026-80000
Severity: CRITICAL
Base Score: 9.3
CVSS Version: 4.0
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 Vector Analysis
Below is the complete, human-readable breakdown of the CVSS metric string: 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
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Attack Vector (AV): Network
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Attack Complexity (AC): Low
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Attack Requirements (AT): None
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Privileges Required (PR): None
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User Interaction (UI): None
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Vulnerability Confidentiality Impact (VC): High
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Vulnerability Integrity Impact (VI): High
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Vulnerability Availability Impact (VA): High
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Subsequent Confidentiality Impact (SC): None
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Subsequent Integrity Impact (SI): None
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Subsequent Availability Impact (SA): None
Affected Vendors & Systems
Vendor
Cotonti
References & Advisory Links
- https://github.com/Cotonti/Cotonti/issues/1888
- https://github.com/Cotonti/Cotonti/pull/1889
- https://github.com/Cotonti/Cotonti/blob/1.0.0/plugins/comments/inc/CommentsWidget.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/comments.setup.php
- https://github.com/Cotonti/Cotonti
- https://www.vulncheck.com/advisories/cotonti-1.0.0-comments-plugin-php-object-injection-via-ci-parameter
Metadata Profile
Database Authority
European Union Agency for Cybersecurity (ENISA) EUVD
Assigner
VulnCheck
EPSS Probability
0
Known Aliases
CVE-2026-91939
GHSA-xv9c-9hwm-jp8g
Published On
2026-09-15
Last Updated
2026-09-16