7.5High
CVE-2026-93872
Cotonti 1.0.0 passes the base64-decoded cb parameter to unserialize() without allowed_classes restriction in the comments plugin EditAction. Registered users with comment write permissions can instantiate arbitrary PHP objects and potentially achieve file write or code execution through gadget chains.
What this means for your business
- An attacker can use it remotely, over a network, with an ordinary user login, and without anyone at your company clicking anything.
What to do
- 1Ask your IT team or provider whether any of your systems use the affected product.
- 2If you do, follow the vendor's guidance. No patch reference has been published yet.
Not sure if your company is exposed?
Fastnexa’s certified penetration testers can check whether attackers could use this flaw, or others like it, against your websites, apps and network. The full test is free for our first 10 founding clients until 31 December 2026.
Scoring
- CVSS
- 7.5 (v3.1)
- Vector
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H- CVSS v4
- 7.7
- Weakness
- CWE-502
- Assigned by
- disclosure@vulncheck.com
Dates
- Published
- 2026-09-18
- Last modified
- 2026-09-21
- Sources
- NVD
References
- https://github.com/Cotonti/Cotonti
- https://github.com/Cotonti/Cotonti/blob/1.0.0/plugins/comments/controllers/actions/EditAction.php
- https://github.com/Cotonti/Cotonti/blob/1.0.0/system/cache.php
- https://github.com/Cotonti/Cotonti/issues/1894
- https://github.com/Cotonti/Cotonti/pull/1897
- https://www.vulncheck.com/advisories/cotonti-1.0.0-php-object-injection-via-comments-plugin-edit-action-cb-parameter