CVE-2026-119428 in phpMyAdmin
Summary
by MITRE • 10/30/2026
phpMyAdmin through 5.2.3 contains a server-side request forgery vulnerability that allows unauthenticated attackers to trigger outbound connections via setup/validate.php, which lacks the setup-disabled guard. Attackers can POST attacker-chosen host and port values reaching Validator::testDBConnection() to open MySQL-protocol connections and probe internal ports using returned error messages.
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Analysis
by VulDB Data Team • 10/30/2026
The vulnerability identified in phpMyAdmin versions through 5.2.3 represents a critical server-side request forgery flaw rooted in the improper handling of unauthenticated requests within the setup subsystem. Specifically, the endpoint located at setup/validate.php fails to enforce the necessary configuration guard that restricts access during or after the installation process. In standard deployments, this script is intended for initial configuration and should be disabled once phpMyAdmin is operational to prevent unauthorized interaction with internal validation mechanisms. However, due to a missing check for the setup-disabled state, unauthenticated remote attackers can interact directly with this endpoint without prior authentication credentials. This architectural oversight effectively bypasses security controls designed to limit exposure of administrative or diagnostic functions to external networks.
The technical mechanism of exploitation involves an attacker sending a POST request to the vulnerable validate.php script containing specifically crafted host and port parameters. These inputs are passed directly into the Validator::testDBConnection() function, which is designed to test database connectivity by attempting to establish connections. Because this function initiates outbound network connections based on user-supplied input without adequate sanitization or restriction of allowed protocols and destinations, it can be abused as a vector for server-side request forgery. The application attempts to open MySQL-protocol connections to the specified host and port, thereby allowing an attacker to direct internal traffic from the vulnerable server to arbitrary targets within the network infrastructure.
The operational impact of this vulnerability extends beyond simple data exfiltration or remote code execution in its immediate form; it serves primarily as a powerful network reconnaissance tool for attackers. By manipulating the returned error messages generated by failed connection attempts, an attacker can perform port scanning and service detection against internal systems that may not be directly accessible from the external internet. The presence or absence of specific MySQL protocol errors allows the attacker to infer whether a target host is reachable and if a database service is listening on a particular port. This capability significantly aids in mapping internal network topologies, identifying vulnerable services such as exposed databases, and planning further attacks against high-value assets within the protected environment.
This vulnerability aligns with CWE-918, which describes Server-Side Request Forgery (SSRF), specifically involving the ability to make requests from a server to unintended destinations due to insufficient validation of user-supplied input. Furthermore, in terms of adversary behavior mapping under the MITRE ATT&CK framework, this exploit technique corresponds to T1572, Protocol Tunneling, as it leverages legitimate application functionality to establish covert communication channels or probe internal networks using standard protocols like MySQL. It also relates to T1046, Network Service Discovery, where attackers use indirect methods to identify active services on internal hosts that are not directly exposed to the attacker's network segment.
Mitigation strategies must focus immediately on restricting access to administrative and setup interfaces. Administrators should ensure that the setup directory is completely removed or disabled in production environments by setting the $cfg['DisableSetup'] configuration option to true within the phpMyAdmin configuration file. Additionally, web server configurations such as Apache or Nginx rules can be employed to explicitly deny HTTP requests to paths containing /setup/ for any user except those originating from trusted internal IP addresses during active installation phases. Regular security audits and patch management are essential to address known vulnerabilities in widely used open-source tools like phpMyAdmin, ensuring that outdated versions with documented flaws are not left exposed on public-facing servers or accessible via reverse proxies without adequate access controls.