CVE-2026-81907 — Concretecms
CVE-2026-81907 is a Cross-Site Request Forgery (CSRF) vulnerability. No vendor fix is recorded yet; mitigation options are listed below.
Concrete CMS 9.5.2 and below is vulnerable to Cross-Site Request Forgery (CSRF) vin Express delete_entries allowing mass deletion of all entity records
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
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
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.
Detection & mitigation playbook
VulnerabilityDetect
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`). Because exploitation targets the running service rather than your application code, O3 also flags the exploit behaviour from runtime telemetry and egress traffic.
Remediation status
No fixed release is recorded for CVE-2026-81907 yet. Track the upstream advisory, and apply the exposure-reduction steps below in the meantime.
Mitigate without a patch
Reduce reachability while you patch: restrict network access to the service to trusted sources, disable or gate the affected component where your deployment allows it, and add a WAF/IPS signature if one exists for CVE-2026-81907. O3's runtime protection blocks the cross-site request forgery (csrf) flaw at execution, which holds the line on hosts you cannot patch immediately.
How O3 protects you
O3 detects and blocks CVE-2026-81907 exploitation at runtime with eBPF exploit-chain detection, plus L7 egress monitoring that catches a post-exploitation callback and cuts the attacker's outbound channel.
Tailored to CVE-2026-81907. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2026-81907 in your dependencies?
O3 Security finds CVE-2026-81907 across dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.