Privilege escalation in Concrete Cms

CVE-2026-8327

Concrete CMS below 9.5.0 and below is vulnerable to password change without reauthorization and session-hardening bypass. The user-profile edit controller passes the entire raw POST array to UserInfo::update() without field whitelisting resulting in password change without requiring the current password  and also resulting in registered users able to disable the per-user-IP-pinning in the session validator which is meant to detect hijacking.  The Concrete CMS security team gave this vulnerability a CVSS v.4.0 score of 5.3 with vector CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N. Thanks 0x4c616e for reporting.

Vulnerability class: Privilege Escalation

Published · last modified .

CVSS v3 metric

CVSS v3 base score 4.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N.

EPSS exploit prediction

EPSS: 0.003 (20.9th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 21st percentile — 20.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-8327: held from 0.002 to 0.003.

EPSS over last 30 days · oldest: 0.002 · newest: 0.003 · change: +0.001

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-8327?
CVE-2026-8327 is a medium-severity vulnerability in Concrete Cms, classified under Improper Privilege Management. CVSS score: 4.3/10. Published 2026-05-21.
How severe is CVE-2026-8327?
Medium severity. CVSS v3 base score is 4.3 out of 10.