CVE-2026-27760
CriticalExploitedPublic exploitOpenCATS PHP Code Injection via installer AJAX endpoint
Published Apr 28, 2026 · Updated Aug 12, 2026
Key Facts
Patch immediately- CVE-2026-27760 is a critical-severity vulnerability (CVSS 9.2 v4) affecting OpenCATS.
- It is exploited in the wild, listed in Industry KEV feed since Jun 17, 2026. Public exploit code is available.
- EPSS estimates a 3.4% probability of exploitation in the next 30 days.
- No fixed version is listed yet; check the vendor advisory for mitigations.
- Brandefense priority: patch immediately, because it is listed as exploited in the wild.
CVSS v4
9.2
CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
EPSS (30-day exploit likelihood)
3.4%
Higher than 88.7% of all scored CVEs
Exploited in the wild
Yes
1 catalog listing
Public exploit code
Available
Proof-of-concept or weaponized module
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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.
Known-Exploited Catalog Listings
| Catalog | Added | Remediation due | Ransomware use |
|---|---|---|---|
| Industry KEV feed | Jun 17, 2026 | n/a | Not reported |
Required action: Apply remediations or mitigations per vendor instructions or discontinue use of the product if remediation or mitigations are unavailable.
Affected Products
1 affected entries in total| Product | Affected versions | Fixed in |
|---|---|---|
| OpenCATS | See advisory | n/a |
Timeline
Publicly disclosed
Apr 28, 2026
Added to Industry KEV feed
Jun 17, 2026
Last updated
Aug 12, 2026
Weakness Type
- CWE-94 Improper Control of Generation of Code ('Code Injection')
References
- advisoryhttps://github.com/CVEProject/cvelistV5/tree/main/cves/2026/27xxx/CVE-2026-27760.json
- advisoryhttps://nvd.nist.gov/vuln/detail/CVE-2026-27760
- advisoryhttps://www.vulncheck.com/advisories/opencats-php-code-injection-via-installer-ajax-endpoint
- patchhttps://github.com/opencats/OpenCATS/commit/3002a29f4c3cada1aa2c4f3d4ae4e189906606b6
- exploithttps://chocapikk.com/posts/2026/opencats-installer-rce/
FAQ
Common Questions.
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.
Affected: OpenCATS. The full list is in the CVE brief.
It is exploited in the wild, listed in Industry KEV feed since Jun 17, 2026.
No, it is not currently listed in the CISA Known Exploited Vulnerabilities catalog.
Public exploit code is available.
No fixed version is listed yet; check the vendor advisory for mitigations.
Brandefense priority: patch immediately, because it is listed as exploited in the wild.
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