CVE-2026-73292 in Semaphore
Summary
by MITRE • 08/12/2026
Semaphore UI is a web interface for managing DevOps tools. Prior to 2.18.21, the /api/users/{id}/password endpoint accepts a cross-site request using the authenticated user's semaphore session cookie without CSRF protection or current-password confirmation, allowing an unauthenticated attacker to change an administrator's or another user's password after user interaction. This issue is fixed in version 2.18.21.
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Analysis
by VulDB Data Team • 08/12/2026
The vulnerability resides within Semaphore UI's authentication mechanism, specifically targeting the /api/users/{id}/password endpoint that lacks proper cross-site request forgery protection. This flaw represents a critical security weakness that enables unauthorized password changes through session hijacking techniques. The absence of CSRF tokens or current-password verification creates an exploitable condition where attackers can manipulate user accounts without legitimate authorization. The vulnerability is particularly dangerous because it allows authenticated session reuse to perform privilege escalation attacks against administrator accounts, potentially leading to complete system compromise. This type of vulnerability falls under CWE-352, which specifically addresses Cross-Site Request Forgery weaknesses in web applications.
The technical exploitation of this vulnerability requires an attacker to craft a malicious request that leverages the victim's existing authenticated session cookie. When a user visits a malicious website or clicks on a crafted link, the browser automatically includes the semaphore session cookie in the background request to the vulnerable endpoint. Without proper CSRF protection mechanisms such as anti-forgery tokens or referer validation, the system cannot distinguish between legitimate requests initiated by the user and malicious requests generated by an attacker. The vulnerability also lacks current-password confirmation requirements, meaning attackers do not need to know the existing password before changing it, making the attack surface significantly broader.
The operational impact of this vulnerability extends beyond simple credential theft to encompass complete account takeover scenarios that could lead to persistent system compromise. An attacker who successfully exploits this vulnerability can change administrator passwords and gain elevated privileges within the DevOps environment. This creates a pathway for privilege escalation attacks that align with ATT&CK technique T1078.004, which covers valid accounts used for unauthorized access. The implications are particularly severe in CI/CD environments where Semaphore UI manages critical deployment workflows, as compromised administrator credentials could enable attackers to modify pipeline configurations, inject malicious code, or gain access to production systems.
Organizations using Semaphore UI versions prior to 2.18.21 should immediately implement mitigations including upgrading to the patched version and deploying additional security controls. The fix implemented in version 2.18.21 addresses the core issue by introducing proper CSRF protection mechanisms and requiring current-password confirmation before allowing password changes. Additional defensive measures include implementing Content Security Policy headers, enabling SameSite cookies for session management, and deploying web application firewalls to detect and block suspicious requests. Network segmentation strategies should also be considered to limit lateral movement if credential compromise occurs. The vulnerability demonstrates the critical importance of CSRF protection in applications handling sensitive user data and administrative functions. Security teams should conduct thorough penetration testing to verify that all authentication endpoints properly implement CSRF protection mechanisms. This issue serves as a reminder of the fundamental security principle that authenticated operations requiring privilege escalation must always include multiple verification layers, including current-password confirmation and proper anti-CSRF controls, to prevent unauthorized access to critical system resources.