SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityAnalyzed

CVE-2026-8353

Concrete CMS version 9.0 to 9.5.0 is vulnerable to Stored XSS via page name in the Atomik theme.

LOW 2.1EPSS 0.15%

Does this matter?

Lower severity and a low EPSS score (0.15%). Track it; it rarely justifies an emergency change on its own.

Description

Concrete CMS version 9.0 to 9.5.0 is vulnerable to Stored XSS via page name in the Atomik theme. A rogue editor can inject arbitrary JavaScript that executes in the context of any authenticated user visiting the affected account pages. This can lead to session hijacking, credential theft, malicious actions performed on behalf of users, and potential privilege escalation. The Concrete CMS security team gave this vulnerability a CVSS v.4.0 score of 2.1 with vector CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N. Thanks Yonatan Drori (Tenzai) for reporting.

CVSS 4.0
2.1 LOWCVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M
EPSS
0.15% probability · 4th percentile
CISA KEV
Not listed
Weakness
CWE-79
Affected
concretecms/concrete cms
Source
ff5b8ace-8b95-4078-9743-eac1ca5451de

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.