Is CVE-2026-8417 actively exploited?

No active exploitation of CVE-2026-8417 has been confirmed so far. Continue monitoring, as exploit status can change.

Can CVE-2026-8417 be exploited remotely?

Yes. CVE-2026-8417 is exploitable remotely over the network (CVSS attack vector: Network).

What is the CVSS score of CVE-2026-8417?

CVE-2026-8417 has a CVSS score of 8.8 (HIGH).

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HIGH

CVE-2026-8417

CWE-352Published: May 21, 2026· Updated: May 26, 2026

8.8

CVSS v3.1

EPSS:0.02%probability of exploitation in 30 daysPercentile:5.4th

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.

NVD Source

Technical Analysis

CVE-2026-8417 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

Exploitation does not require any privileges, though user interaction (Required) is needed, which slightly reduces the risk of mass automated attacks.

A successful exploit results in complete confidentiality breach (data exposure), full integrity compromise (data manipulation), availability disruption (denial of service), with a CVSS base score of 8.8.