CVE-2026-8139

MEDIUM

Concrete CMS 9.5.0 and below is vulnerable to Stored XSS via external-link page cvName

Title source: cna
STIX 2.1

Description

Concrete CMS 9.5.0 and below is vulnerable to Stored XSS via external-link page cvName because updateCollectionAliasExternal bypasses being sanitized. The Concrete CMS security team gave this vulnerability a CVSS v.4.0 score of 2.0 with vector CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:P/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N.  Thanks Yonatan Drori (Tenzai) for reporting.

References (1)

Core 1

Scores

CVSS v3 5.4
EPSS 0.0015
EPSS Percentile 4.5%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N

CISA SSVC

Vulnrichment
Exploitation none
Automatable no
Technical Impact partial

Details

CWE
CWE-79
Status published
Products (2)
Concrete CMS/Concrete CMS 5.0 - 9.5.0
concretecms/concrete_cms < 9.5.0
Published May 21, 2026
Tracked Since May 22, 2026