CVE-2026-55559 Yamcs: Remote Code Execution via instance-template argument YAML injection (createInstance)

Yamcs is a mission control framework. Prior to 5.12.8 and 5.13.2, Yamcs inserts templateArgs from POST /api/instances and PATCH /api/instances/instance into YAML through VarStatement.append in yamcs-core/src/main/java/org/yamcs/templating/VarStatement.java without YAML-context escaping. The...

CVE-2026-55559 Yamcs: Remote Code Execution via instance-template argument YAML injection (createInstance)

Yamcs is a mission control framework. Prior to 5.12.8 and 5.13.2, Yamcs inserts templateArgs from POST /api/instances and PATCH /api/instances/instance into YAML through VarStatement.append in yamcs-core/src/main/java/org/yamcs/templating/VarStatement.java without YAML-context escaping. The...

CVE-2026-55559

CVE-2026-55559 is a Critical (CVSS 9.8) remote code execution vulnerability in Yamcs (mission control framework) prior to versions 5.12.8 and 5.13.2 . The root cause is that templateArgs submitted via POST /api/instances or PATCH /api/instances/{instance} are appended into the rendered YAML confi...

EUVD-2026-67843

Yamcs is a mission control framework. Prior to 5.12.8 and 5.13.2, Yamcs inserts templateArgs from POST /api/instances and PATCH /api/instances/instance into YAML through VarStatement.append in yamcs-core/src/main/java/org/yamcs/templating/VarStatement.java without YAML-context escaping. The...

Directory Traversal

Overview Affected versions of this package are vulnerable to Directory Traversal via improper validation of user-supplied paths in the HttpRequestHandler.java and StaticFileHandler.java components. An attacker can access arbitrary files on the underlying operating system by sending specially...

Yamcs has Unauthenticated Directory Traversal

Attack type: Unauthenticated remote Impact: Attackers can access any system files from the underlying host. Affected components: HttpRequestHandler.java, StaticFileHandler.java An Unauthenticated Directory Traversal vulnerability exists in Yamcs Steps to Reproduce: 1. Start Yamcs and login as a...

GHSA-9JG3-G3WH-W9PJ Yamcs has Unauthenticated Directory Traversal

Attack type: Unauthenticated remote Impact: Attackers can access any system files from the underlying host. Affected components: HttpRequestHandler.java, StaticFileHandler.java An Unauthenticated Directory Traversal vulnerability exists in Yamcs Steps to Reproduce: 1. Start Yamcs and login as a...

CVE-2026-55552

Yamcs is a mission control framework affected by an unauthenticated directory traversal in StaticFileHandler.locateFile (yamcs-core). The method resolves request paths without calling Path.normalize and Path.toAbsolutePath to verify the result stays within the configured staticRoots, allowing tra...

CVE-2026-55552 Yamcs: Unauthenticated Directory Traversal

Yamcs is a mission control framework. Prior to 5.11.13, Yamcs StaticFileHandler.locateFile resolves an unauthenticated request path without using Path.normalize and Path.toAbsolutePath to confirm that the absolute path remains within the configured staticRoots. A path containing traversal segment...

CVE-2026-55552 Yamcs: Unauthenticated Directory Traversal

Yamcs is a mission control framework. Prior to 5.11.13, Yamcs StaticFileHandler.locateFile resolves an unauthenticated request path without using Path.normalize and Path.toAbsolutePath to confirm that the absolute path remains within the configured staticRoots. A path containing traversal segment...

CVE-2026-55552 Yamcs: Unauthenticated Directory Traversal

Yamcs is a mission control framework. Prior to 5.11.13, Yamcs StaticFileHandler.locateFile resolves an unauthenticated request path without using Path.normalize and Path.toAbsolutePath to confirm that the absolute path remains within the configured staticRoots. A path containing traversal segment...

EUVD-2026-67842

Yamcs is a mission control framework. Prior to 5.11.13, Yamcs StaticFileHandler.locateFile resolves an unauthenticated request path without using Path.normalize and Path.toAbsolutePath to confirm that the absolute path remains within the configured staticRoots. A path containing traversal segment...

Cross-site Scripting (XSS)

Overview Affected versions of this package are vulnerable to Cross-site Scripting XSS via the authorize.html process. An attacker can execute arbitrary JavaScript in a user's browser by tricking the user into visiting a specially crafted URL, which can result in the exfiltration of session tokens...

GHSA-RXPG-WJF8-QV9C Yamcs has Reflected XSS in the URL of the Authorize Endpoint

Attack type: Unauthenticated remote Impact: Attackers can execute arbitrary JavaScript in a user's browser, including obtaining a user's session token and refresh token. Affected components: authorize.html, AuthHandler.java, HandlerContext.java A Reflected Cross-Site Scripting vulnerability...

Yamcs has Reflected XSS in the URL of the Authorize Endpoint

Attack type: Unauthenticated remote Impact: Attackers can execute arbitrary JavaScript in a user's browser, including obtaining a user's session token and refresh token. Affected components: authorize.html, AuthHandler.java, HandlerContext.java A Reflected Cross-Site Scripting vulnerability...

CVE-2026-55549 Yamcs: Reflected XSS in the URL of the Authorize Endpoint

Yamcs is a mission control framework. Prior to 5.9.4, Yamcs reflects an attacker-controlled redirecturi parameter from GET /auth/authorize into yamcs-core/src/main/resources/auth/templates/authorize.html without adequate HTML escaping by yamcs-core/src/main/java/org/yamcs/http/auth/AuthHandler.ja...

EUVD-2026-67841

Yamcs is a mission control framework. Prior to 5.9.4, Yamcs reflects an attacker-controlled redirecturi parameter from GET /auth/authorize into yamcs-core/src/main/resources/auth/templates/authorize.html without adequate HTML escaping by yamcs-core/src/main/java/org/yamcs/http/auth/AuthHandler.ja...

CVE-2026-55549 Yamcs: Reflected XSS in the URL of the Authorize Endpoint

Yamcs is a mission control framework. Prior to 5.9.4, Yamcs reflects an attacker-controlled redirecturi parameter from GET /auth/authorize into yamcs-core/src/main/resources/auth/templates/authorize.html without adequate HTML escaping by yamcs-core/src/main/java/org/yamcs/http/auth/AuthHandler.ja...

CVE-2026-55549 Yamcs: Reflected XSS in the URL of the Authorize Endpoint

Yamcs is a mission control framework. Prior to 5.9.4, Yamcs reflects an attacker-controlled redirecturi parameter from GET /auth/authorize into yamcs-core/src/main/resources/auth/templates/authorize.html without adequate HTML escaping by yamcs-core/src/main/java/org/yamcs/http/auth/AuthHandler.ja...

CVE-2026-55549

Yamcs , an open-source mission control framework, is vulnerable to reflected cross-site scripting (XSS) in the redirect_uri parameter of the GET /auth/authorize endpoint. The parameter is reflected into authorize.html without adequate HTML escaping by AuthHandler.java and HandlerContext.java , al...