What is CVE-2026-8135?

CVE-2026-8135 is a high-severity vulnerability in Concrete Cms, classified under Deserialization of Untrusted Data. CVSS score: 7.2/10. Published 2026-05-21.

How severe is CVE-2026-8135?

High severity. CVSS v3 base score is 7.2 out of 10.

Deserialization in Concrete Cms

CVE-2026-8135

Concrete CMS 9.5.0 and below is vulnerable to Remote Code Execution due to insecure deserialization occurring in the ExpressEntryList block controller. An rogue administrator with privileges to add blocks to an area can bypass the intende…

Vulnerability class: Insecure Deserialization

EPSS: 0.002 (46.2th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 7.2 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H.

Affected products

Concrete Cms — versions 5.0
Concretecms Concrete_cms

Weakness classification (CWE)

CWE-502 — Deserialization of Untrusted Data

References

ff5b8ace-8b95-4078-9743-eac1ca5451de (release-notes, Release Notes)

Frequently asked questions

What is CVE-2026-8135?: CVE-2026-8135 is a high-severity vulnerability in Concrete Cms, classified under Deserialization of Untrusted Data. CVSS score: 7.2/10. Published 2026-05-21.
How severe is CVE-2026-8135?: High severity. CVSS v3 base score is 7.2 out of 10.