Vulnerability details

CVE-2026-8417

Concrete CMS Concrete CMS

Concrete CMS 9.5.0 and below is vulnerable to CSRF in do_update() in the package update controller

CVSS 4.0
7.5High

Official description

Concrete CMS 9.5.0 and below does not validate a CSRF token before processing requests to /dashboard/extend/update/do_update/<pkgHandle>. The do_update() method in concrete/controllers/single_page/dashboard/extend/update.php checks only canInstallPackages() before executing upgradeCoreData() and upgrade() on the named package's controller. Because the endpoint is a state-changing GET route with no token enforcement, an attacker can force an authenticated administrator to trigger a package upgrade via a single cross-site navigation.In order to be vulnerable, the victim must be passing canInstallPackages() and and a target package must already be already installed. The Concrete CMS security team gave this vulnerability a CVSS v.4.0 score of 7.5 with vector CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N. Thanks  https://github.com/maru1009  for reporting.

CVSS scores

ScoreVersionSourceVector
7.5High 4.0 CVEProject cvelistV5 (CNA) (ConcreteCMS) CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

Affected products

VendorProductVersionsSource
Concrete CMS Concrete CMS 5.0 ≤ v ≤ 9.5.0 CVEProject cvelistV5 (CNA)

References and advisories

1
Kolun on Telegram @kolunsec Exploited CVEs, key news and a daily digest Alerts for this product's next CVEsFollow the product to get new vulnerabilities on Telegram.

Details

Published
2026-05-21
Last updated
2026-05-22
State
Published
Assigner (CNA)
ConcreteCMS

Exploit prediction (EPSS)

0.12%
Probability of exploitation in 30 days
1.9%
Percentile (among all CVEs)

SSVC assessment (CISA)

Automatable
No
Exploitation
None
Technical impact
Total

Weaknesses (CWE)

  • CWE-352
    Cross-Site request forgery (CSRF)