{"id":"CVE-2026-55549","state":"PUBLISHED","title":"Yamcs: Reflected XSS in the URL of the Authorize Endpoint","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.","publishedAt":"2026-08-28T17:15:52.840Z","updatedAt":"2026-09-01T01:49:34.239Z","severity":{"score":6.5,"label":"Medium","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N","source":"GitHub_M"},"assigner":"GitHub_M","products":["yamcs yamcs"],"affected":[{"vendor":"yamcs","product":"yamcs","versions":[{"version":"< 5.9.4","status":"affected"}]}],"references":["https://github.com/yamcs/yamcs/security/advisories/GHSA-rxpg-wjf8-qv9c","https://github.com/yamcs/yamcs/commit/4d47d5cdcf5d92c2c5bbbc19feada422923332e3","https://github.com/yamcs/yamcs/releases/tag/yamcs-5.9.4"],"weaknesses":["CWE-79"],"ingestedAt":"2026-10-29T20:12:24.861Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/55xxx/CVE-2026-55549.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-55549","state":"PUBLISHED","datePublished":"2026-08-28T17:15:52.840Z","dateUpdated":"2026-09-01T01:49:34.239Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2026-06-16T23:01:04.075Z"},"containers":{"cna":{"title":"Yamcs: Reflected XSS in the URL of the Authorize Endpoint","descriptions":[{"lang":"en","value":"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."}],"affected":[{"vendor":"yamcs","product":"yamcs","versions":[{"version":"< 5.9.4","status":"affected"}]}],"references":[{"url":"https://github.com/yamcs/yamcs/security/advisories/GHSA-rxpg-wjf8-qv9c","name":"https://github.com/yamcs/yamcs/security/advisories/GHSA-rxpg-wjf8-qv9c","tags":["x_refsource_CONFIRM"]},{"url":"https://github.com/yamcs/yamcs/commit/4d47d5cdcf5d92c2c5bbbc19feada422923332e3","name":"https://github.com/yamcs/yamcs/commit/4d47d5cdcf5d92c2c5bbbc19feada422923332e3","tags":["x_refsource_MISC"]},{"url":"https://github.com/yamcs/yamcs/releases/tag/yamcs-5.9.4","name":"https://github.com/yamcs/yamcs/releases/tag/yamcs-5.9.4","tags":["x_refsource_MISC"]}],"metrics":[{"cvssV3_1":{"attackComplexity":"LOW","attackVector":"NETWORK","availabilityImpact":"NONE","baseScore":6.5,"baseSeverity":"MEDIUM","confidentialityImpact":"HIGH","integrityImpact":"NONE","privilegesRequired":"NONE","scope":"UNCHANGED","userInteraction":"REQUIRED","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N","version":"3.1"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-79","lang":"en","description":"CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')","type":"CWE"}]}],"providerMetadata":{"shortName":"GitHub_M","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateUpdated":"2026-08-28T17:15:52.840Z"},"source":{"advisory":"GHSA-rxpg-wjf8-qv9c","discovery":"UNKNOWN"}},"adp":[{"title":"CISA ADP Vulnrichment","references":[{"url":"https://github.com/yamcs/yamcs/security/advisories/GHSA-rxpg-wjf8-qv9c","tags":["exploit"]}],"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-09-01T01:48:54.496048Z","id":"CVE-2026-55549","options":[{"Exploitation":"poc"},{"Automatable":"no"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-09-01T01:49:34.239Z"}}]}}}