{"document":{"category":"csaf_vex","csaf_version":"2.0","title":"CVE-2026-55197: Hermes WebUI < 0.51.443 - Broken Access Control in /api/session Endpoint","publisher":{"category":"vendor","name":"HarborGuard Database","namespace":"https://database.harborguard.co"},"tracking":{"id":"CVE-2026-55197","status":"final","version":"1","initial_release_date":"2026-06-17T17:59:10.933Z","current_release_date":"2026-06-17T18:51:38.359Z","revision_history":[{"date":"2026-06-17T17:59:10.933Z","number":"1","summary":"Initial machine-readable export from HarborGuard."}]},"distribution":{"tlp":{"label":"WHITE"},"text":"Public CVE data; freely redistributable."},"notes":[{"category":"description","text":"Hermes WebUI before 0.51.443 contains a broken access control vulnerability in the /api/session endpoint that allows authenticated users to disclose cross-profile session transcripts. Attackers can bypass profile boundary checks by directly querying session IDs belonging to other profiles via GET /api/session?session_id=<foreign_id>&messages=1 to retrieve unauthorized conversation transcripts and metadata.","title":"CVE description"}],"references":[{"category":"self","summary":"CVE-2026-55197 on HarborGuard Database","url":"https://database.harborguard.co/cve/CVE-2026-55197"},{"category":"external","summary":"CVE Record","url":"https://www.cve.org/CVERecord?id=CVE-2026-55197"},{"category":"external","summary":"Release Notes","url":"https://github.com/nesquena/hermes-webui/releases/tag/v0.51.443"},{"category":"external","summary":"Researcher Pull Request","url":"https://github.com/nesquena/hermes-webui/pull/3982"},{"category":"external","summary":"Maintainer Pull Request","url":"https://github.com/nesquena/hermes-webui/pull/4269"},{"category":"external","summary":"Patch Commit","url":"https://github.com/nesquena/hermes-webui/commit/2a3baa71b81ca92da8ece8616a09f15894beec71"},{"category":"external","summary":"vulncheck.com","url":"https://www.vulncheck.com/advisories/hermes-webui-broken-access-control-in-api-session-endpoint"}]},"product_tree":{"branches":[{"category":"vendor","name":"nesquena","branches":[{"category":"product_name","name":"hermes-webui","branches":[{"category":"product_version_range","name":"<0.51.443","product":{"name":"nesquena hermes-webui <0.51.443","product_id":"CSAFPID-1","product_identification_helper":{"cpe":"cpe:2.3:a:nesquena:hermes-webui:*:*:*:*:*:*:*:*"}}},{"category":"product_version","name":"0.51.443","product":{"name":"nesquena hermes-webui 0.51.443","product_id":"CSAFPID-2","product_identification_helper":{"cpe":"cpe:2.3:a:nesquena:hermes-webui:*:*:*:*:*:*:*:*"}}}]}]}]},"vulnerabilities":[{"cve":"CVE-2026-55197","title":"Hermes WebUI < 0.51.443 - Broken Access Control in /api/session Endpoint","notes":[{"category":"description","text":"Hermes WebUI before 0.51.443 contains a broken access control vulnerability in the /api/session endpoint that allows authenticated users to disclose cross-profile session transcripts. Attackers can bypass profile boundary checks by directly querying session IDs belonging to other profiles via GET /api/session?session_id=<foreign_id>&messages=1 to retrieve unauthorized conversation transcripts and metadata.","title":"CVE description"}],"product_status":{"known_affected":["CSAFPID-1"],"fixed":["CSAFPID-2"]},"scores":[{"cvss_v4":{"version":"4.0","vectorString":"CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N","baseScore":7.1,"baseSeverity":"HIGH"},"products":["CSAFPID-1"]}],"remediations":[{"category":"vendor_fix","details":"Update to a fixed version: 0.51.443.","product_ids":["CSAFPID-1"],"url":"https://github.com/nesquena/hermes-webui/commit/2a3baa71b81ca92da8ece8616a09f15894beec71"}]}]}