CVE-2026-57297: 
Jenkins vulnerability analysis and mitigation

CVE-2026-57297 is a missing permission check vulnerability in the Jenkins Contrast Continuous Application Security Plugin (versions 3.11 and earlier) that allows attackers with Overall/Read permission to connect to an attacker-specified URL using an attacker-specified username, API key, and service key. It is part of a broader security advisory (SECURITY-3697 (1)) that also covers a related CSRF issue (CVE-2026-57298). The vulnerability was disclosed on June 24, 2026, and has a CVSS v3.1 base score of 4.3 (Medium) (Jenkins Advisory, GitHub Advisory).

The root cause is CWE-862 (Missing Authorization): the plugin's HTTP endpoint for testing connections to a Contrast TeamServer does not enforce any permission check beyond the basic Overall/Read permission, which is typically granted to all authenticated users. An attacker can craft a request to this endpoint supplying arbitrary URL, username, API key, and service key values, causing the Jenkins server to initiate an outbound connection to an attacker-controlled host. Additionally, the endpoint accepts GET requests (no POST requirement), enabling cross-site request forgery (CSRF) attacks as a companion vector (CVE-2026-57298). The vulnerability was reported by Kai Aizen (SnailSploit) (Jenkins Advisory).

Exploitation allows a low-privileged authenticated attacker (or, via CSRF, an unauthenticated attacker tricking a logged-in user) to cause the Jenkins controller to make outbound HTTP connections to arbitrary attacker-controlled URLs, potentially enabling server-side request forgery (SSRF) against internal network resources. The integrity impact is low — attackers can influence connection behavior but cannot directly read or exfiltrate Jenkins credentials through this specific flaw. Availability and confidentiality are not directly impacted by CVE-2026-57297 alone, though the SSRF capability could be chained with other vulnerabilities for broader compromise (Jenkins Advisory, GitHub Advisory).

1. Reconnaissance: Identify Jenkins instances running the Contrast Continuous Application Security Plugin version 3.11 or earlier. This can be done by browsing to the Jenkins plugin manager or using tools like Shodan to find exposed Jenkins instances.
2. Obtain Overall/Read access: Log in with any low-privileged Jenkins account that has Overall/Read permission, which is commonly granted to all authenticated users in many Jenkins deployments.
3. Identify the vulnerable endpoint: Locate the HTTP endpoint used to test the connection to a Contrast TeamServer (typically a form validation or connection-test endpoint within the plugin's configuration UI).
4. Craft a malicious request: Send a GET or POST request to the vulnerable endpoint, supplying attacker-controlled values for the URL, username, API key, and service key parameters — directing the connection to an attacker-controlled server (e.g., a Burp Collaborator or similar out-of-band listener).
5. Capture the outbound connection: Observe the Jenkins controller initiating an outbound HTTP request to the attacker-specified URL, confirming SSRF and potentially revealing internal network topology or enabling further attacks.
6. (CSRF variant): Alternatively, craft a malicious web page that triggers the GET request to the vulnerable endpoint when visited by a logged-in Jenkins user, achieving the same effect without requiring direct credentials (Jenkins Advisory).

• Network: Unexpected outbound HTTP/HTTPS connections from the Jenkins controller to unknown or external IP addresses, particularly originating from the Jenkins process and not associated with configured SCM or build targets.
• Logs: Jenkins access logs showing GET requests to the Contrast plugin's connection-test endpoint (e.g., paths containing contrast or teamserver in the URL) with unusual or external host parameters; repeated requests from low-privileged user accounts.
• Process: Jenkins controller process initiating connections to IPs or domains not in the expected allow-list for Contrast TeamServer configurations.

Update the Contrast Continuous Application Security Plugin to version 3.12 or later, which requires Overall/Administer permission and POST requests to test the connection to a Contrast TeamServer, eliminating both the missing permission check and the CSRF vector (Jenkins Advisory). As an interim workaround, restrict Overall/Read access to trusted users only, and consider blocking outbound connections from the Jenkins controller to untrusted external hosts via network-level controls. Administrators should also review and apply all other fixes from the June 24, 2026 Jenkins security advisory, as multiple plugins were affected simultaneously.

The vulnerability was disclosed as part of a broad Jenkins security advisory covering over 20 CVEs across 18 plugins, which received coverage from standard vulnerability tracking services including Tenable (Nessus plugin 322478), OSS-Sec mailing list, and VulnDB. No notable independent researcher commentary or significant social media discussion specific to CVE-2026-57297 has been identified beyond routine advisory aggregation (Jenkins Advisory, GitHub Advisory).