{"id":"CVE-2026-55549","url":"https://www.cyber-defence.io/tools/cve/CVE-2026-55549","generatedAt":"2026-10-28T00:14:40.189Z","title":"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…","description":"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 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.","published":"2026-08-28T20:18:29.000Z","lastModified":"2026-09-08T21:08:37.000Z","status":"Awaiting Analysis","sourceIdentifier":"security-advisories@github.com","cvss":{"version":"3.1","score":6.5,"severity":"MEDIUM","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N"},"cwe":["CWE-79"],"affected":[],"epss":{"score":0.01305,"percentile":0.70332,"date":"2026-10-26","history":[]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"low","text":"Lower severity and a low EPSS score (1.31%). Track it; it rarely justifies an emergency change on its own."},"changes":[],"references":[{"url":"https://github.com/yamcs/yamcs/commit/4d47d5cdcf5d92c2c5bbbc19feada422923332e3","source":"security-advisories@github.com"},{"url":"https://github.com/yamcs/yamcs/releases/tag/yamcs-5.9.4","source":"security-advisories@github.com"},{"url":"https://github.com/yamcs/yamcs/security/advisories/GHSA-rxpg-wjf8-qv9c","source":"security-advisories@github.com"},{"url":"https://github.com/yamcs/yamcs/security/advisories/GHSA-rxpg-wjf8-qv9c","source":"134c704f-9b21-4f2e-91b3-4a467353bcc0"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-55549","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}