CVE-2026-71981

Cypht < 2.12.2 PHP Object Injection RCE via back_query Parameter

HIGH
8.8
CVSS Score
Published: September 1, 2026 at 08:43 PM UTC
Updated: September 8, 2026 at 08:29 PM UTC
1 product affected across 1 vendorCypht

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Severity
HIGH8.8
Exploit prediction
EPSS 1.0%
SSVC
No known exploit

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v < 2.12.2
Affected range stops below 2.12.2, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

SSVC — Action Prioritization

SSVCNo known exploitNot automatableTotal impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

8.8HIGHVulnCheck
Attack Vector
NETWORK
Complexity
LOW
Privileges
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
HIGH
Integrity
HIGH
Availability
HIGH
Vector?

Quick Info

StatusDEFERRED
CWE
CWE-502

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