CVE-2026-8340

MEDIUM

Concrete CMS 9.5.0 and below is vulnerable to CSRF via Backend\File::approveVersion

Title source: cna
STIX 2.1

Description

Concrete CMS 9.5.0 and below is vulnerable to CSRF via Backend\File::approveVersion. Victim with edit_file_contents permission is CSRF'd into publishing an attacker-chosen previously-uploaded version (downgrade to an older version of a file, or activation of a co-editor's unpublished version). The Concrete CMS security team gave this vulnerability a CVSS v.4.0 score of 2.3 with vector CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N. Thanks Winston Crooker for reporting.

References (1)

Core 1

Scores

CVSS v3 4.3
EPSS 0.0013
EPSS Percentile 2.7%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N

CISA SSVC

Vulnrichment
Exploitation none
Automatable no
Technical Impact partial

Details

CWE
CWE-352
Status published
Products (2)
Concrete CMS/Concrete CMS 5.0 - 9.5.0
concretecms/concrete_cms < 9.5.1
Published May 22, 2026
Tracked Since May 22, 2026