Deserialization in Cypht-Org Cypht
CVE-2026-71981
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.
Vulnerability class: Insecure Deserialization
CVSS v3 metric
CVSS v3 base score 8.8 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.
Affected products
Weakness classification (CWE)
References
- disclosure@vulncheck.com (release-notes)
- disclosure@vulncheck.com (issue-tracking)
- disclosure@vulncheck.com (patch)
- disclosure@vulncheck.com (third-party-advisory)
Frequently asked questions
- What is CVE-2026-71981?
- CVE-2026-71981 is a high-severity vulnerability in Cypht-Org Cypht, classified under Deserialization of Untrusted Data. CVSS score: 8.8/10. Published 2026-09-01.
- How severe is CVE-2026-71981?
- High severity. CVSS v3 base score is 8.8 out of 10.