What is the CVSS score of CVE-2025-34061?

CVE-2025-34061 has a CVSS 4.0 base score of 9.3 (Critical). CVSS vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N. EPSS exploitation probability: 59.2%.

Which versions of PHP are affected by CVE-2025-34061?

Organizations using PHPStudy face critical risk from CVE-2025-34061, a code injection vulnerability rated CVSS 9.3.

Is there a public PoC exploit available for CVE-2025-34061?

Yes, a public proof-of-concept exploit is available for CVE-2025-34061. Prioritise patching immediately. EPSS: 59.2%.

How to fix or mitigate CVE-2025-34061?

Within 24 hours: Identify all affected systems running PHPStudy and apply vendor patches immediately. Validate that input sanitization is in place for all user-controlled parameters.

PHP CVE-2025-34061

EUVD-2025-19906 CRITICAL

Code Injection (CWE-94)

2025-07-03 disclosure@vulncheck.com

PHP RCE Code Injection

9.3

CVSS 4.0 · NVD

Severity by source

NVD PRIMARY

9.3 CRITICAL

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

Primary rating from NVD · only source for this CVE.

CVSS VectorNVD

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Lifecycle Timeline

EUVD ID Assigned

Mar 16, 2026 - 02:12 euvd

EUVD-2025-19906

Analysis Generated

Mar 16, 2026 - 02:12 vuln.today

CVE Published

Jul 03, 2025 - 20:15 nvd

CRITICAL 9.3

DescriptionCVE.org

A backdoor in PHPStudy versions 2016 through 2018 allows unauthenticated remote attackers to execute arbitrary PHP code on affected installations. The backdoor listens for base64-encoded PHP payloads in the Accept-Charset HTTP header of incoming requests, decodes and executes the payload without proper validation. This leads to remote code execution as the web server user, compromising the affected system.

AnalysisAI

PHPStudy development environment versions 2016 through 2018 contain an embedded backdoor that executes arbitrary PHP code from HTTP request headers. The backdoor listens for base64-encoded payloads in the Accept-Charset header, decodes and executes them without any authentication, providing complete remote code execution on any server running the compromised PHPStudy.

Technical ContextAI

PHPStudy bundles Apache+PHP+MySQL for Windows development. Versions 2016-2018 were distributed with a backdoor that intercepts every HTTP request and checks the Accept-Charset header for base64-encoded PHP code. If found, the code is decoded and executed via eval(). This affects every website hosted on the compromised PHPStudy installation.

RemediationAI

Reinstall PHPStudy from verified sources or migrate to XAMPP/WAMP. Never use PHPStudy in production. Audit servers that ran PHPStudy 2016-2018 for compromise indicators. Consider all data on affected servers as potentially exfiltrated.