{"id":"CVE-2026-10054","state":"PUBLISHED","title":"In affected versions of Eclipse Theia (1.8.1 and later), the browser backend exposes privileged terminal RPC over WebSocket (/services/shell-terminal, /services/terminals/:id) with","description":"In affected versions of Eclipse Theia (1.8.1 and later), the browser backend exposes privileged terminal RPC over WebSocket (/services/shell-terminal, /services/terminals/:id) without service-level authentication.\n\n\n\n\nWebSocket origin validation in @theia/core is fail-open: connections are accepted when the Origin header is missing or when no THEIA_HOSTS allowlist is configured (the default). The Socket.IO integration additionally replaces the real Origin header with a client-supplied fix-origin header that an attacker can control or omit.\n\n\n\n\nAs a result, a foreign-origin web page visited by a user with a running Theia instance can open the /services WebSocket namespace, invoke terminal creation, attach to the resulting terminal data channel, execute arbitrary OS commands, and read their output. This affects both local developer setups (drive-by attack) and hosted or tunneled deployments without strong external authentication.\n\n\n\n\nA fix is in development that enforces same-origin validation by default, removes trust in the fix-origin header, gates HTTP and WebSocket access on a SameSite=Strict; HttpOnly connection-token cookie, and sanitizes shell terminal creation options.","publishedAt":"2026-07-03T10:11:32.446Z","updatedAt":"2026-07-07T03:56:07.775Z","severity":{"score":8.8,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H","source":"eclipse"},"assigner":"eclipse","products":["Eclipse Foundation Eclipse Theia"],"affected":[{"vendor":"Eclipse Foundation","product":"Eclipse Theia","defaultStatus":"unaffected","versions":[{"version":"1.8.1","status":"affected","lessThan":"1.73.0","versionType":"semver"}]}],"references":["https://github.com/eclipse-theia/theia/security/advisories/GHSA-78g8-vm3p-97c6","https://gitlab.eclipse.org/security/vulnerability-reports/-/work_items/376"],"weaknesses":["CWE-1385","CWE-306"],"ingestedAt":"2026-10-29T20:10:33.477Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/10xxx/CVE-2026-10054.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-10054","state":"PUBLISHED","datePublished":"2026-07-03T10:11:32.446Z","dateUpdated":"2026-07-07T03:56:07.775Z","assignerShortName":"eclipse","assignerOrgId":"e51fbebd-6053-4e49-959f-1b94eeb69a2c","dateReserved":"2026-05-29T07:35:37.279Z"},"containers":{"cna":{"descriptions":[{"lang":"en","value":"In affected versions of Eclipse Theia (1.8.1 and later), the browser backend exposes privileged terminal RPC over WebSocket (/services/shell-terminal, /services/terminals/:id) without service-level authentication.\n\n\n\n\nWebSocket origin validation in @theia/core is fail-open: connections are accepted when the Origin header is missing or when no THEIA_HOSTS allowlist is configured (the default). The Socket.IO integration additionally replaces the real Origin header with a client-supplied fix-origin header that an attacker can control or omit.\n\n\n\n\nAs a result, a foreign-origin web page visited by a user with a running Theia instance can open the /services WebSocket namespace, invoke terminal creation, attach to the resulting terminal data channel, execute arbitrary OS commands, and read their output. This affects both local developer setups (drive-by attack) and hosted or tunneled deployments without strong external authentication.\n\n\n\n\nA fix is in development that enforces same-origin validation by default, removes trust in the fix-origin header, gates HTTP and WebSocket access on a SameSite=Strict; HttpOnly connection-token cookie, and sanitizes shell terminal creation options."}],"affected":[{"vendor":"Eclipse Foundation","product":"Eclipse Theia","defaultStatus":"unaffected","versions":[{"version":"1.8.1","status":"affected","lessThan":"1.73.0","versionType":"semver"}]}],"references":[{"url":"https://github.com/eclipse-theia/theia/security/advisories/GHSA-78g8-vm3p-97c6"},{"url":"https://gitlab.eclipse.org/security/vulnerability-reports/-/work_items/376"}],"metrics":[{"format":"CVSS","scenarios":[{"lang":"en","value":"GENERAL"}],"cvssV3_1":{"version":"3.1","attackVector":"NETWORK","attackComplexity":"LOW","privilegesRequired":"NONE","userInteraction":"REQUIRED","scope":"UNCHANGED","confidentialityImpact":"HIGH","integrityImpact":"HIGH","availabilityImpact":"HIGH","baseSeverity":"HIGH","baseScore":8.8,"vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-1385","lang":"en","description":"CWE-1385 Missing origin validation in WebSockets","type":"CWE"}]},{"descriptions":[{"cweId":"CWE-306","lang":"en","description":"CWE-306 Missing authentication for critical function","type":"CWE"}]}],"providerMetadata":{"shortName":"eclipse","orgId":"e51fbebd-6053-4e49-959f-1b94eeb69a2c","dateUpdated":"2026-07-03T10:11:32.446Z"},"impacts":[{"capecId":"CAPEC-111","descriptions":[{"lang":"en","value":"CAPEC-111 JSON Hijacking (aka JavaScript Hijacking)"}]},{"capecId":"CAPEC-62","descriptions":[{"lang":"en","value":"CAPEC-62 Cross Site Request Forgery"}]}],"credits":[{"lang":"en","value":"Anwar Ayoob","type":"reporter"}],"source":{"discovery":"UNKNOWN"},"x_generator":{"engine":"Vulnogram 1.0.2"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-07-06T00:00:00+00:00","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"total"}],"role":"CISA Coordinator","version":"2.0.3","id":"CVE-2026-10054"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-07-07T03:56:07.775Z"}}]}}}