How severe is CVE-2026-81907?

No CVSS score has been assigned to CVE-2026-81907 yet. Review the advisory details and affected package list to assess your exposure.

Which packages are affected by CVE-2026-81907?

Affected package information for CVE-2026-81907 is not yet fully mapped. Check the official advisory links for details.

How do I fix CVE-2026-81907?

Upgrade the affected component to the fixed release for CVE-2026-81907, or apply your distribution's backported patch — distro builds are often patched at an older version number, so check your vendor's advisory rather than the upstream version alone.

How do I detect CVE-2026-81907 in my code and dependencies?

Identify every host running the affected component and compare the installed build against the fixed version below — for source-built or distro-packaged software the version string, not a lockfile, is the source of truth (`dpkg -l`, `rpm -q`, or the binary's own `--version`).

How do I mitigate CVE-2026-81907 if there is no patch (or I can't update yet)?

If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

Is CVE-2026-81907 actively exploited in the wild?

No public exploit code has been indexed for CVE-2026-81907 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for CVE-2026-81907?

CVE-2026-81907 has an EPSS (Exploit Prediction Scoring System) score of 0.1%, placing it in the 3th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is CVE-2026-81907?

CVE-2026-81907 is classified as Cross-Site Request Forgery (CSRF) (CWE-352). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was CVE-2026-81907 published, and has it been updated?

CVE-2026-81907 was published on September 11, 2026 and was last updated on September 26, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

CVE-2026-81907: concretecms CSRF

Exploitation Status

No confirmed exploitation observed yet

CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.

Exploitation and automatability from CISA’s SSVC triage for CVE-2026-81907.

EPSS Exploitation Probability

via FIRST.org ↗

0.1%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs3th percentile — riskier than 3% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

Description

Concrete CMS 9.5.2 and below is vulnerable to Cross-Site Request Forgery (CSRF) in the Express "Clear Entries" function (POST /index.php/dashboard/system/express/entities/delete_entries) because the controller records but does not enforce a failed CSRF token check, allowing the destructive operation to proceed when the token is missing or invalid. A remote unauthenticated attacker can force an authenticated administrator who visits an attacker-controlled page to permanently delete all entries belonging to an attacker-selected Express entity on a web application to which the administrator is currently authenticated. Because the default Contact Express object ships with a fixed entity UUID, the target identifier can be obtained without dashboard access. The Concrete CMS security team gave this vulnerability a CVSS v4.0 score of 6.1 with vector CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:N/VI:H/VA:H/SC:N/SI:N/SA:N. Thanks Pratik Zanjurne for reporting.

Affected Products

1 product · 1 configurations

Application

concrete cmsconcretecms

< 9.5.3

range

Detection & mitigation playbook

Vulnerability

Detect
Identify every host running the affected component and compare the installed build against the fixed version below — for source-built or distro-packaged software the version string, not a lockfile, is the source of truth (`dpkg -l`, `rpm -q`, or the binary's own `--version`).
Fix
Upgrade the affected component to the fixed release for CVE-2026-81907, or apply your distribution's backported patch — distro builds are often patched at an older version number, so check your vendor's advisory rather than the upstream version alone.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

Frequently Asked Questions

Concrete CMS 9.5.2 and below is vulnerable to Cross-Site Request Forgery (CSRF) in the Express "Clear Entries" function (POST /index.php/dashboard/system/express/entities/delete_entries) because the controller records but does not enforce a failed CSRF token check, allowing the destructive operation to proceed when the token is missing or invalid. A remote unauthenticated attacker can force an authenticated administrator who visits an attacker-controlled page to permanently delete all entries belonging to an attacker-selected Express entity on a web application to which the administrator is cu

O3 Security · Impact-Aware SCA

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CVE-2026-81907 — concretecms