{"id":"CVE-2026-34403","state":"PUBLISHED","title":"Nginx-UI vulnerable to Cross-Site WebSocket Hijacking (CSWSH) via missing origin validation on all WebSocket endpoints","description":"Nginx UI is a web user interface for the Nginx web server. Prior to version 2.3.5, all WebSocket endpoints in nginx-ui use a gorilla/websocket Upgrader with CheckOrigin unconditionally returning true, allowing Cross-Site WebSocket Hijacking (CSWSH). Combined with the fact that authentication tokens are stored in browser cookies (set via JavaScript without HttpOnly or explicit SameSite attributes), a malicious webpage can establish authenticated WebSocket connections to the nginx-ui instance when a logged-in administrator visits the attacker-controlled page. Version 2.3.5 patches the issue.","publishedAt":"2026-04-20T20:16:47.597Z","updatedAt":"2026-04-21T13:36:46.510Z","severity":{"score":5.5,"label":"Medium","version":"4.0","vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/E:P","source":"GitHub_M"},"assigner":"GitHub_M","products":["0xJacky nginx-ui"],"affected":[{"vendor":"0xJacky","product":"nginx-ui","versions":[{"version":"< 2.3.5","status":"affected"}]}],"references":["https://github.com/0xJacky/nginx-ui/security/advisories/GHSA-78mf-482w-62qj","https://github.com/0xJacky/nginx-ui/releases/tag/v2.3.5"],"weaknesses":["CWE-1385"],"ingestedAt":"2026-10-29T20:11:40.391Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/34xxx/CVE-2026-34403.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-34403","state":"PUBLISHED","datePublished":"2026-04-20T20:16:47.597Z","dateUpdated":"2026-04-21T13:36:46.510Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2026-03-27T13:45:29.620Z"},"containers":{"cna":{"title":"Nginx-UI vulnerable to Cross-Site WebSocket Hijacking (CSWSH) via missing origin validation on all WebSocket endpoints","descriptions":[{"lang":"en","value":"Nginx UI is a web user interface for the Nginx web server. Prior to version 2.3.5, all WebSocket endpoints in nginx-ui use a gorilla/websocket Upgrader with CheckOrigin unconditionally returning true, allowing Cross-Site WebSocket Hijacking (CSWSH). Combined with the fact that authentication tokens are stored in browser cookies (set via JavaScript without HttpOnly or explicit SameSite attributes), a malicious webpage can establish authenticated WebSocket connections to the nginx-ui instance when a logged-in administrator visits the attacker-controlled page. Version 2.3.5 patches the issue."}],"affected":[{"vendor":"0xJacky","product":"nginx-ui","versions":[{"version":"< 2.3.5","status":"affected"}]}],"references":[{"url":"https://github.com/0xJacky/nginx-ui/security/advisories/GHSA-78mf-482w-62qj","name":"https://github.com/0xJacky/nginx-ui/security/advisories/GHSA-78mf-482w-62qj","tags":["x_refsource_CONFIRM"]},{"url":"https://github.com/0xJacky/nginx-ui/releases/tag/v2.3.5","name":"https://github.com/0xJacky/nginx-ui/releases/tag/v2.3.5","tags":["x_refsource_MISC"]}],"metrics":[{"cvssV4_0":{"attackVector":"NETWORK","attackComplexity":"LOW","attackRequirements":"NONE","privilegesRequired":"NONE","userInteraction":"ACTIVE","vulnConfidentialityImpact":"NONE","vulnIntegrityImpact":"HIGH","vulnAvailabilityImpact":"NONE","subConfidentialityImpact":"NONE","subIntegrityImpact":"NONE","subAvailabilityImpact":"NONE","baseScore":5.5,"baseSeverity":"MEDIUM","vectorString":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/E:P","version":"4.0"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-1385","lang":"en","description":"CWE-1385: Missing Origin Validation in WebSockets","type":"CWE"}]}],"providerMetadata":{"shortName":"GitHub_M","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateUpdated":"2026-04-20T20:16:47.597Z"},"source":{"advisory":"GHSA-78mf-482w-62qj","discovery":"UNKNOWN"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-04-21T13:36:34.314909Z","id":"CVE-2026-34403","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":"2026-04-21T13:36:46.510Z"}}]}}}