CVE-2026-71981

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.

CVSS Vector

References

• https://github.com/cypht-org/cypht/commit/e4aa2f34e33f9328e8c93514cc3966fc3d99925e
• https://github.com/cypht-org/cypht/pull/2073
• https://github.com/cypht-org/cypht/releases/tag/v2.12.2
• https://www.vulncheck.com/advisories/cypht-php-object-injection-rce-via-back-query-parameter