What is CVE-2026-93872?

CVE-2026-93872 is a high-severity vulnerability in Cotonti, classified under Deserialization of Untrusted Data. CVSS score: 7.5/10. Published 2026-09-18.

How severe is CVE-2026-93872?

High severity. CVSS v3 base score is 7.5 out of 10.

Deserialization in Cotonti

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.

Vulnerability class: Insecure Deserialization

Published 2026-09-18 · last modified 2026-09-22.

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.007 (53.5th percentile), scored 2026-11-02.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 54th percentile — 53.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.007 · newest: 0.007 · change: 0.000

Affected products

Cotonti

Weakness classification (CWE)

CWE-502 — Deserialization of Untrusted Data

References

github.com/Cotonti/Cotonti/issues/1894 (issue-tracking)
github.com/Cotonti/Cotonti/pull/1897 (issue-tracking, patch)
github.com/Cotonti/Cotonti/blob/1.0.0/plugins/comments/controllers/actions/Edit… (technical-description)
github.com/Cotonti/Cotonti/blob/1.0.0/system/cache.php (technical-description)
github.com/Cotonti/Cotonti (product)
www.vulncheck.com/advisories/cotonti-1.0.0-php-object-injection-via-comments-pl… (third-party-advisory)

Frequently asked questions

What is CVE-2026-93872?: CVE-2026-93872 is a high-severity vulnerability in Cotonti, classified under Deserialization of Untrusted Data. CVSS score: 7.5/10. Published 2026-09-18.
How severe is CVE-2026-93872?: High severity. CVSS v3 base score is 7.5 out of 10.