{"id":"CVE-2026-55549","title":"Yamcs is a mission control framework","summary":"Yamcs is a mission control framework. Prior to 5.9.4, Yamcs reflects an attacker-controlled redirect_uri parameter from GET /auth/authorize into yamcs-core/src/main/resources/auth/templates/authorize.html without adequate HTML escaping b…","severity":"medium","cvss":6.5,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N","cwe":["CWE-79"],"vendor":"yamcs","product":"org.yamcs:yamcs-core","affected":["org.yamcs:yamcs-core < 5.9.4"],"patched":["org.yamcs:yamcs-core 5.9.4"],"published":"2026-08-28","updated":"2026-09-08","sourceUpdated":"2026-09-08T21:08:37.320","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-55549","references":[{"url":"https://github.com/yamcs/yamcs/commit/4d47d5cdcf5d92c2c5bbbc19feada422923332e3","label":"security-advisories@github.com"},{"url":"https://github.com/yamcs/yamcs/releases/tag/yamcs-5.9.4","label":"security-advisories@github.com"},{"url":"https://github.com/yamcs/yamcs/security/advisories/GHSA-rxpg-wjf8-qv9c","label":"security-advisories@github.com"},{"url":"https://github.com/yamcs/yamcs/security/advisories/GHSA-rxpg-wjf8-qv9c","label":"134c704f-9b21-4f2e-91b3-4a467353bcc0"},{"url":"https://github.com/advisories/GHSA-rxpg-wjf8-qv9c"}],"tags":["nvd","ghsa","maven","exploit-available"],"epss":0.00897,"epssPercentile":0.57565,"aliases":["GHSA-rxpg-wjf8-qv9c"],"ecosystem":"maven","ingestedAt":"2026-08-28T17:22:56.076Z","exploits":{"nuclei":["CVE-2026-55549"],"checkedAt":"2026-09-21T15:29:37.985Z"},"exploitAvailable":true,"slug":"CVE-2026-55549","body":"## Overview\n\nYamcs is a mission control framework. Prior to 5.9.4, Yamcs reflects an attacker-controlled redirect_uri 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.java and yamcs-core/src/main/java/org/yamcs/http/HandlerContext.java. A crafted authorization URL can execute JavaScript when opened by a Yamcs user. The script can access browser-held authentication material and transmit it to an attacker, enabling account compromise. This issue is fixed in version 5.9.4.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.\n\n## Package advisory (CVE-2026-55549)\n\nAffected packages:\n\n- `org.yamcs:yamcs-core < 5.9.4`\n\nPatched in:\n\n- `org.yamcs:yamcs-core 5.9.4`\n\nSource: https://github.com/advisories/GHSA-rxpg-wjf8-qv9c","depth":"twilight","depthScore":48,"depthScoreParts":{"impact":35.8,"likelihood":0.2,"exploitation":12,"ransomware":0},"changes":[{"seq":207753,"id":"CVE-2026-55549","ts":1789837253477,"field":"exploit_available","old":"false","new":"true"}]}