What is CVE-2026-27760?

CVE-2026-27760 is a high-severity vulnerability in Opencats, classified under Code Injection. CVSS score: 8.1/10. Published 2026-04-28.

How severe is CVE-2026-27760?

High severity. CVSS v3 base score is 8.1 out of 10.

Is CVE-2026-27760 known to be exploited?

1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.

RCE in Opencats

CVE-2026-27760

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.

Vulnerability class: RCE (Remote Code Execution)

Published 2026-04-28 · last modified 2026-07-14.

CVSS v3 metric

CVSS v3 base score 8.1 (High). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.034 (88.8th percentile), scored 2026-10-20.

Low probability of exploitation in the next 30 days, but still tracked. 89th percentile — 88.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.346 · newest: 0.034 · change: -0.312

Affected products

Opencats — versions 0, 3002a29f4c3cada1aa2c4f3d4ae4e189906606b6

Weakness classification (CWE)

CWE-94 — Code Injection

Public proof-of-concept exploits

rapid7/metasploit-framework

References

chocapikk.com/posts/2026/opencats-installer-rce/ (technical-description, exploit)
github.com/opencats/OpenCATS/pull/706 (issue-tracking)
github.com/opencats/OpenCATS/commit/3002a29f4c3cada1aa2c4f3d4ae4e189906606b6 (patch)
github.com/opencats/OpenCATS/blob/46e4727/lib/CATSUtility.php (related)
github.com/opencats/OpenCATS/blob/46e4727/modules/install/ajax/ui.php (related)
www.vulncheck.com/advisories/opencats-php-code-injection-via-installer-ajax-end… (third-party-advisory)

Frequently asked questions

What is CVE-2026-27760?: CVE-2026-27760 is a high-severity vulnerability in Opencats, classified under Code Injection. CVSS score: 8.1/10. Published 2026-04-28.
How severe is CVE-2026-27760?: High severity. CVSS v3 base score is 8.1 out of 10.
Is CVE-2026-27760 known to be exploited?: 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.