{"id":"CVE-2026-54617","summary":"GravitLauncher: Unauthenticated path traversal in LaunchServer FileServerHandler","details":"GravitLauncher is an open-source Minecraft launcher based on sashok724's v3. Prior to 5.7.12, an unauthenticated remote actor can send a raw HTTP request target without a leading slash to the default LaunchServer file server on port 9274. FileServerHandler.channelRead0 in components/launchserver/src/main/java/pro/gravit/launchserver/socket/handlers/fileserver/FileServerHandler.java strips the first request-target character and resolves the remaining path against updatesDir without re-normalizing and verifying containment. This leaves parent-directory components in a no-leading-slash request and allows reading any file accessible to the LaunchServer process, including .keys/ecdsa_id, .keys/legacySalt, and LaunchServer.json. Disclosure of those files can expose signing keys, refresh-token material, and database credentials, enabling forged administrative access tokens and full authentication bypass. A normalizing L7 proxy may block the primary request form, but direct exposure and L4/TCP proxies remain affected, and netty.fileServerEnabled is enabled by default. This issue is fixed in 5.7.12.","aliases":["GHSA-5g75-477j-2c2f"],"modified":"2026-09-19T08:14:22.333150Z","published":"2026-09-17T18:34:40.563Z","database_specific":{"cna_assigner":"GitHub_M","cwe_ids":["CWE-200","CWE-22","CWE-522"],"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/54xxx/CVE-2026-54617.json"},"references":[{"type":"WEB","url":"https://github.com/GravitLauncher/Launcher/releases/tag/v5.7.12"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/54xxx/CVE-2026-54617.json"},{"type":"ADVISORY","url":"https://github.com/GravitLauncher/Launcher/security/advisories/GHSA-5g75-477j-2c2f"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-54617"},{"type":"FIX","url":"https://github.com/GravitLauncher/Launcher/commit/8114a1d4cfbcaab4c1c337d921597805d71dee3b"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/gravitlauncher/launcher","events":[{"introduced":"0"},{"fixed":"8114a1d4cfbcaab4c1c337d921597805d71dee3b"},{"fixed":"fef9bae63da1afc0518d32e3333db20f409ab196"}],"database_specific":{"extracted_events":[{"introduced":"0"},{"fixed":"5.7.12"}],"source":["AFFECTED_FIELD","REFERENCES"]}}],"versions":["v5.7.1b3","v5.2.6","v5.2.2","v5.2.0-stable","v5.0.0b4","v4.2.1-stable","v4.1.0b8-beta","v4.1.0b7-beta","v4.0.8-stable","v4.0.7-stable","v4.0.6-beta","v4.0.2-beta","v4.0.1-beta","v4.0.0b3-dev","v4.0.0b2-dev","v4.0.0b1-dev"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-54617.json","vanir_signatures_modified":"2026-09-19T08:14:22Z","vanir_signatures":[{"signature_type":"Function","signature_version":"v1","source":"https://github.com/gravitlauncher/launcher/commit/8114a1d4cfbcaab4c1c337d921597805d71dee3b","target":{"file":"components/launchserver/src/main/java/pro/gravit/launchserver/socket/handlers/fileserver/FileServerHandler.java","function":"channelRead0"},"deprecated":false,"digest":{"function_hash":"323079498020791883804598656217973970550","length":2427},"id":"CVE-2026-54617-67aadb5d"},{"signature_version":"v1","source":"https://github.com/gravitlauncher/launcher/commit/8114a1d4cfbcaab4c1c337d921597805d71dee3b","target":{"file":"components/launchserver/src/main/java/pro/gravit/launchserver/socket/handlers/fileserver/FileServerHandler.java"},"deprecated":false,"digest":{"line_hashes":["191750727599073554647365754052379144490","167667344567132132347785472687221676011","120447054406221686181754940568006858668","246429432771504280264388284389552894830"],"threshold":0.9},"id":"CVE-2026-54617-89bfab9e","signature_type":"Line"},{"digest":{"line_hashes":["111772859681101315033004083644853869087","173186182574712184695790095105448094590","205849670440004851523507195535414807689","4948600106563056388344395260209482005"],"threshold":0.9},"id":"CVE-2026-54617-c89b7b90","signature_type":"Line","signature_version":"v1","source":"https://github.com/gravitlauncher/launcher/commit/fef9bae63da1afc0518d32e3333db20f409ab196","target":{"file":"components/launcher-core/src/main/java/pro/gravit/utils/Version.java"},"deprecated":false}]}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"}]}