CVE-2026-8340
published 2026-05-22CVE-2026-8340: 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…
PriorityP420medium4.3CVSS 3.1
AVNACLPRNUIRSUCNILAN
EPSS
0.10%
1.2th percentile
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an attacker-chosen previously-uploaded version (downgrade to an older version of a file, or activation of a co-editor's unpublished version).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.
Affected
3 ranges
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| concrete5 | concrete5 | >= 0 < 9.5.1 | 9.5.1 |
| concrete_cms | concrete_cms | 5.0 – 9.5.0 | — |
| concretecms | concrete_cms | < 9.5.1 | 9.5.1 |
CVSS provenance
nvdv3.14.3MEDIUMCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N
nvdv4.02.3LOWCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:N/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/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
cvelistv5v4.02.3LOWCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N
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GHSA
GHSA-xjg6-5v39-v7fc: Concrete CMS 9
ghsa_unreviewed·2026-05-26
CVE-2026-8340 [LOW] CWE-352 GHSA-xjg6-5v39-v7fc: Concrete CMS 9
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an attacker-chosen previously-uploaded version (downgrade to an older version of a file, or activation of a co-editor's unpublished version).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.
GHSA
Concrete CMS is vulnerable to CSRF via Backend\File::approveVersion
ghsa·2026-05-26
CVE-2026-8340 [LOW] CWE-352 Concrete CMS is vulnerable to CSRF via Backend\File::approveVersion
Concrete CMS is vulnerable to CSRF via Backend\File::approveVersion
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). Thanks Winston Crooker for reporting.
VulDB
Concrete CMS up to 9.5.0 edit_file_contents cross-site request forgery
vuldb·2026-05-22
CVE-2026-8340 [LOW] Concrete CMS up to 9.5.0 edit_file_contents cross-site request forgery
A vulnerability, which was classified as problematic, has been found in Concrete CMS up to 9.5.0. Impacted is the function edit_file_contents. Performing a manipulation results in cross-site request forgery.
This vulnerability is known as CVE-2026-8340. Remote exploitation of the attack is possible. No exploit is available.
CVEList
Concrete CMS 9.5.0 and below is vulnerable to CSRF via Backend\File::approveVersion
cvelistv5·2026-05-22·CVSS 2.3
CVE-2026-8340 [LOW] CWE-352 Concrete CMS 9.5.0 and below is vulnerable to CSRF via Backend\File::approveVersion
Concrete CMS 9.5.0 and below is vulnerable to CSRF via Backend\File::approveVersion
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.
No detection rules found.
No public exploits indexed.
No writeups or analysis indexed.
2026-05-22
Published