CVE-2026-8340
Concrete CMS 9.5.0 and below is vulnerable to CSRF via Backend\File::approveVersion
Vexday Risk Score
8Low
SSVC decision (CISA)
Track
No exploitation signal → monitor
CVSS 2.3EPSS 0.1%KEV nãoPoC —Nuclei —Metasploit —Patch —
Lifecycle
22 May 2026Published on NVD
Recommendation: Monitor — no exploitation signal at the moment.
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an attacker-chosen previously-uploaded version (downgrade to an older version of a file, or activation of a co-editor's unpublished version).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.
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
Affected products
Concrete CMS · Concrete CMSWant to know if your infrastructure is exposed to this?
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