Is CVE-2026-8340 actively exploited?

No active exploitation of CVE-2026-8340 has been confirmed so far. Continue monitoring, as exploit status can change.

Can CVE-2026-8340 be exploited remotely?

Yes. CVE-2026-8340 is exploitable remotely over the network (CVSS attack vector: Network).

What is the CVSS score of CVE-2026-8340?

CVE-2026-8340 has a CVSS score of 4.3 (MEDIUM).

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MEDIUM

CVE-2026-8340

CWE-352Published: May 22, 2026· Updated: May 26, 2026

4.3

CVSS v3.1

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

Official 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an attacker-chosen previously-uploaded version (downgrade to an older version of a file, or activation of a co-editor's unpublished version).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.

NVD Source

Technical Analysis

CVE-2026-8340 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.