Cypht < 2.12.2 PHP Object Injection RCE via back_query Parameter (CVE-2026-71981) | HOL Guard CVE

Unknown severity · Source severity not reportedCVE-2026-71981

Cypht < 2.12.2 PHP Object Injection RCE via back_query Parameter

Answer in brief

CVE-2026-71981 records a Unknown severity vulnerability in Cypht < 2.12.2 PHP Object Injection RCE via back_query Parameter. The current sources do not mark it as known exploited. The current feed maps cypht-org/cypht (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Sep 1, 2026Updated Sep 1, 2026Source checked Sep 1, 2026First seen by HOL Sep 1, 2026Material review Sep 1, 2026

Upstream Advisory

Key facts

Risk: Unknown severitySource severity not reported
Exploitation: Not marked as known exploited
Affected software: 1 mapped package or product
Fix availability: Available

Why this deserves its current priority

A CVSS score is not reported in the current record. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps cypht-org/cypht (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
cypht-org/cyphtgeneric	>=0 <2.12.2	2.12.2

Recommended response

Check inventory. Check lockfiles and deployed manifests for cypht-org/cypht.
Review the reported fix. Update cypht-org/cypht to 2.12.2 if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

Published upstream
Sep 1, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Sep 1, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Sep 1, 2026

Sources and claim methodology

Upstream source 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.

Quoted source text, attributed separately from HOL analysis.