CVE-2026-71981CWE-502insecure-deserialization

CVE-2026-71981

High · published September 2, 2026

CVSS v3.1
8.8
EPSS
1%
Percentile
61.6
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS v3.1
8.8 · HIGH
Vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
CVSS v4.0
8.7 · 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
EPSS
0.00972 · 61.6th percentile
Weakness
CWE-502 · Deserialization of Untrusted Data
Published
2026-09-02T01:18Z
References (4)
EPSS history
Timeline
  • 03 SEP 03:31Z
    EPSS moved — → 1%
    epss
  • 01 SEP 20:43Z
    Cypht < 2.12.2 PHP Object Injection RCE via back_query Parameter
    cvelistv5