CVE-2026-71981
Cypht < 2.12.2 PHP Object Injection RCE via back_query Parameter
- State
- Published
- Severity
- 8.7 High
- Published
- Sep 1, 2026
- Updated
- Sep 2, 2026
- Reserved
- Aug 8, 2026
Description
Cypht before 2.12.2 contains a PHP object injection vulnerability that allows authenticated attackers to execute arbitrary operating system commands by supplying a crafted PHP object graph in the back_query GET parameter of the logout handler. Attackers can pass a base64-encoded serialized payload through this parameter, which is decoded and passed directly to unserialize() without an allow-list, signature check, or type restriction, enabling gadget-chain exploitation to achieve remote code execution as the web server process.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 4.0 | 8.7 High | CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N | VulnCheck |
| 3.1 | 8.8 High | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H | VulnCheck |
Weaknesses
- CWE-502 Deserialization of Untrusted Data
Affected Products
| Product | Versions |
|---|---|
cyphtcypht-org |
|
References
- Release Notesrelease-notes
- Pull Requestissue-tracking
- Patch Commitpatch
- https://www.vulncheck.com/advisories/cypht-php-object-injection-rce-via-back-query-parameterthird-party-advisory
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