CVE-2026-84662 in LDAP Plugin
Summary
by MITRE • 09/02/2026
Jenkins LDAP Plugin 807.809.vd3a_4e5e4ec98 and earlier allows connecting to a specified URL through Stapler data binding, allowing attackers to connect to an attacker-specified URL.
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Analysis
by VulDB Data Team • 09/02/2026
The Jenkins LDAP plugin versions 807.809.vd3a_4e5e4ec98 and earlier contain a critical security flaw rooted in improper validation of user-supplied input within the Stapler web framework integration. This vulnerability arises from the way the plugin handles data binding for configuration parameters, specifically those related to LDAP server connections. When an administrator configures or modifies authentication settings through the Jenkins graphical interface or API, the underlying Java code utilizes Staplers automatic data binding mechanism to map form fields directly to object properties without sufficient sanitization of the target URL string. This architectural oversight allows a malicious actor with administrative privileges on the Jenkins instance to inject arbitrary URLs into these configuration fields.
The core technical flaw is classified under CWE-918, which addresses Server-Side Request Forgery (SSRF). By manipulating the LDAP server URL field, an attacker can force the Jenkins application server to initiate HTTP or other protocol-based connections to destinations of their choosing. This capability bypasses standard network perimeter defenses because the requests originate from within the trusted internal network where Jenkins is hosted. The Stapler framework processes these inputs as part of its normal configuration update routine, meaning the malicious request appears legitimate to intermediate security controls such as firewalls and intrusion detection systems that might otherwise block external connections initiated by untrusted users.
The operational impact of this vulnerability extends beyond simple information disclosure. An attacker with administrative access can leverage SSRF to probe internal network services that are not exposed to the public internet, including database servers, internal APIs, cloud metadata endpoints, or other sensitive infrastructure components. This can lead to unauthorized data exfiltration from internal systems, exploitation of vulnerabilities in backend services through crafted requests, and potential lateral movement within the organization's network environment. In environments where Jenkins is integrated with various CI/CD pipelines and deployment tools, compromising these internal resources could result in widespread disruption or further compromise of critical business applications.
This vulnerability aligns with MITRE ATT&CK technique T1598, specifically Phishing for Information via Web Services, as it involves the abuse of legitimate web service functionality to gather information about the target environment. It also relates to T1071 Application Layer Protocol, where the attacker uses standard HTTP/S protocols to exfiltrate data or communicate with command and control infrastructure if such capabilities are combined with other exploits. The risk is particularly severe in Jenkins deployments that run as privileged users on Linux systems, as successful exploitation could potentially lead to remote code execution depending on how the SSRF payload interacts with backend services like Redis or Elasticsearch which may have their own authentication weaknesses.
Mitigation strategies must focus on immediate remediation and long-term architectural hardening. The primary recommendation is to upgrade the Jenkins LDAP plugin to version 807.810.vd3a_4e5e4ec98 or later, where this input validation issue has been addressed by implementing strict URL parsing and allow-listing mechanisms that prevent arbitrary host resolution. For organizations unable to patch immediately due to compatibility constraints, restricting administrative access through robust identity management solutions can reduce the attack surface. Additionally, deploying network-level controls such as egress filtering rules on Jenkins hosts can limit outbound connections to only known trusted domains, thereby mitigating the impact of SSRF even if an attacker manages to trigger it. Regular auditing of plugin configurations and monitoring for unusual outbound traffic patterns from CI/CD servers are also essential defensive measures.