Vulnerability · Published Apr 28, 2026 · Assigned by VulnCheck
CVE-2026-27760OpenCATS PHP Code Injection via installer AJAX endpoint
High 8.1
In plain English
A high-severity code injection in OpenCATS from opencats. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 33.0% (higher than 98% of all known vulnerabilities). Ready-made attack tooling exists: Metasploit, Nuclei.
Official description
OpenCATS prior to commit 3002a29 contains a PHP code injection vulnerability in the installer AJAX endpoint that allows unauthenticated attackers to execute arbitrary code by injecting PHP statements into the databaseConnectivity action parameter. Attackers can break out of the define() string context in config.php using a single quote and statement separator to inject malicious PHP code that persists and executes on every subsequent page load when the installation wizard remains incomplete.
Affected products (as reported)
Weakness: CWE-94 · Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
References
- https://chocapikk.com/posts/2026/opencats-installer-rce/ technical-description, exploit
- https://github.com/opencats/OpenCATS/pull/706 issue-tracking
- https://github.com/opencats/OpenCATS/commit/3002a29f4c3cada1aa2c4f3d4ae4e189906606b6 patch
- https://github.com/opencats/OpenCATS/blob/46e4727/lib/CATSUtility.php#L142-L172 related
- https://github.com/opencats/OpenCATS/blob/46e4727/modules/install/ajax/ui.php#L130 related
- https://www.vulncheck.com/advisories/opencats-php-code-injection-via-installer-ajax-endpoint third-party-advisory