{"id":"GHSA-c39v-8hrw-h448","summary":"Chainlit contains a session hijacking vulnerability","details":"Chainlit before 2.10.1 contains a session hijacking vulnerability that allows unauthenticated attackers to restore and inherit authenticated user sessions by presenting a valid sessionId during WebSocket session restoration without ownership verification. Attackers can exploit the restore_existing_session path to assume a victim's permissions and roles, enabling unauthorized invocation of tools and access to data restricted to the authenticated victim.","aliases":["CVE-2026-56104"],"modified":"2026-09-21T22:30:12.894277651Z","published":"2026-06-22T18:34:16Z","database_specific":{"github_reviewed_at":"2026-09-21T22:21:35Z","nvd_published_at":"2026-06-22T16:16:40Z","cwe_ids":["CWE-862"],"severity":"CRITICAL","github_reviewed":true},"references":[{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-56104"},{"type":"WEB","url":"https://github.com/Chainlit/chainlit/pull/2857"},{"type":"WEB","url":"https://github.com/Chainlit/chainlit/commit/5effb664f1e0af4a4f0a42fe63ea979676039a7f"},{"type":"PACKAGE","url":"https://github.com/Chainlit/chainlit"},{"type":"WEB","url":"https://github.com/Chainlit/chainlit/releases/tag/2.10.1"},{"type":"WEB","url":"https://www.vulncheck.com/advisories/chainlit-session-hijacking-via-websocket-session-restoration"}],"affected":[{"package":{"name":"chainlit","ecosystem":"PyPI","purl":"pkg:pypi/chainlit"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"2.10.1"}]}],"versions":["0.1.0","0.1.1","0.1.101","0.1.102","0.1.103","0.2.0","0.2.1","0.2.101","0.2.102","0.2.103","0.2.104","0.2.105","0.2.106","0.2.107","0.2.108","0.2.109","0.2.110","0.2.111","0.3.0","0.4.0","0.4.1","0.4.101","0.4.2","0.4.3","0.5.0","0.5.1","0.5.2","0.6.0","0.6.1","0.6.2","0.6.3","0.6.4","0.6.401","0.6.402","0.7.0","0.7.1","0.7.2","0.7.3","0.7.301","0.7.400","0.7.500","0.7.501","0.7.600rc0","0.7.600rc1","0.7.601rc0","0.7.602","0.7.602rc0","0.7.603","0.7.604","0.7.604rc0","0.7.604rc1","0.7.604rc2","0.7.700","1.0.0","1.0.0rc0","1.0.0rc1","1.0.0rc2","1.0.0rc3","1.0.100","1.0.101","1.0.200","1.0.300","1.0.301","1.0.400","1.0.401","1.0.500","1.0.501","1.0.502","1.0.503","1.0.504","1.0.505","1.0.506","1.1.0","1.1.0rc0","1.1.0rc1","1.1.101","1.1.200","1.1.201","1.1.202","1.1.300","1.1.300rc0","1.1.300rc1","1.1.300rc2","1.1.300rc3","1.1.300rc4","1.1.300rc5","1.1.301","1.1.302","1.1.303","1.1.304","1.1.305","1.1.306","1.1.400","1.1.400rc0","1.1.400rc1","1.1.401","1.1.402","1.1.403rc0","1.1.404","1.2.0","1.2.0rc0","1.3.0","1.3.0rc0","1.3.0rc1","1.3.1","1.3.2","2.0.0","2.0.1","2.0.2","2.0.3","2.0.4","2.0.5","2.0.6","2.0.601","2.0.602","2.0.603","2.0.dev0","2.0.dev1","2.0.dev2","2.0rc0","2.0rc1","2.1.0","2.1.1","2.1.2","2.10.0","2.2.0","2.2.1","2.3.0","2.4.0","2.4.0rc0","2.4.1","2.4.2","2.4.201","2.4.3","2.4.301","2.4.302","2.4.400","2.5.5","2.6.0","2.6.1","2.6.2","2.6.3","2.6.4","2.6.5","2.6.6","2.6.7","2.6.8","2.6.9","2.7.0","2.7.1","2.7.1.1","2.7.2","2.8.0","2.8.1","2.8.2","2.8.3","2.8.4","2.8.5","2.9.0","2.9.1","2.9.2","2.9.3","2.9.4","2.9.5","2.9.6"],"database_specific":{"source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/06/GHSA-c39v-8hrw-h448/GHSA-c39v-8hrw-h448.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N"},{"type":"CVSS_V4","score":"CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N"}]}