What is the CVSS score of CVE-2026-3839?

CVE-2026-3839 has a CVSS 3.0 base score of 7.3 (High). CVSS vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L. EPSS exploitation probability: 0.3%.

Which versions of PHP are affected by CVE-2026-3839?

CVE-2026-3839 is an unauthenticated remote access vulnerability affecting all versions of Unraid that could allow attackers to bypass login controls and gain full system access without credentials.

How to fix or mitigate CVE-2026-3839?

Within 24 hours: Inventory all Unraid deployments and restrict network access to auth-request.php via firewall rules; document current access logs for signs of exploitation. Within 7 days: Implement WAF rules to block suspicious path traversal patterns targeting auth-request.php; consider disabling remote authentication if not operationally critical. Within 30 days: Monitor vendor (Lime Technology) for patch release; evaluate alternative authentication mechanisms or air-gapping critical Unraid systems from untrusted networks until patched.

PHP CVE-2026-3839

EUVD-2026-12168 HIGH

Path Traversal (CWE-22)

2026-03-13 zdi

Authentication Bypass PHP Path Traversal Unraid

7.3

CVSS 3.0 · NVD

Severity by source

NVD PRIMARY

7.3 HIGH

AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L

Primary rating from NVD · only source for this CVE.

CVSS VectorNVD

CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

Low

Integrity

Low

Availability

Low

Lifecycle Timeline

EUVD ID Assigned

Mar 13, 2026 - 21:01 euvd

EUVD-2026-12168

Analysis Generated

Mar 13, 2026 - 21:01 vuln.today

CVE Published

Mar 13, 2026 - 20:38 nvd

HIGH 7.3

DescriptionCVE.org

Unraid Authentication Request Path Traversal Authentication Bypass Vulnerability. This vulnerability allows remote attackers to bypass authentication on affected installations of Unraid. Authentication is not required to exploit this vulnerability.

The specific flaw exists within the auth-request.php file. The issue results from the lack of proper validation of a user-supplied path prior to using it in authentications. An attacker can leverage this vulnerability to bypass authentication on the system. Was ZDI-CAN-28912.

AnalysisAI

Critical authentication bypass vulnerability in Unraid's auth-request.php file that allows remote attackers to gain unauthorized access without credentials through path traversal exploitation. The vulnerability affects all versions of Unraid (CPE indicates no version restrictions) and can be exploited over the network with low complexity, potentially compromising system confidentiality, integrity, and availability. No KEV listing or EPSS data was provided, suggesting this may be a recently disclosed vulnerability without known active exploitation.

Technical ContextAI

The vulnerability exists in the auth-request.php file within Unraid, a proprietary NAS operating system built on Linux. As a CWE-22 (Path Traversal) vulnerability, attackers can manipulate file paths to access resources outside intended directories, bypassing authentication checks. The flaw stems from insufficient validation of user-supplied path parameters before using them in authentication decisions. Based on the CPE string (cpe:2.3:a:unraid:unraid:*:*:*:*:*:*:*:*), all versions of Unraid appear to be affected, though specific version ranges are not detailed in the available intelligence.

RemediationAI

No specific patch version or remediation steps are available in the provided intelligence. The only reference is to the ZDI advisory (https://www.zerodayinitiative.com/advisories/ZDI-26-172/) which may contain additional details. Organizations running Unraid should monitor the vendor's security advisories for patch releases and apply updates immediately when available. As an interim mitigation, consider restricting network access to Unraid management interfaces through firewall rules or VPN requirements until a patch is released.