CVE-2026-55197
Hermes WebUI < 0.51.443 - Broken Access Control in /api/session Endpoint
CVSS Score
6.5
EPSS Score
0.0%
EPSS Percentile
0th
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.
| CWE | CWE-639 |
| Vendor | nesquena |
| Product | hermes-webui |
| Published | Jun 17, 2026 |
| Last Updated | Jun 17, 2026 |
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CVSS v3 Breakdown
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N Attack Vector
Network
Attack Complexity
Low
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
None
Availability
None
Affected Versions
nesquena / hermes-webui
0 < 0.51.443
References
github.com: https://github.com/nesquena/hermes-webui/releases/tag/v0.51.443 github.com: https://github.com/nesquena/hermes-webui/pull/3982 github.com: https://github.com/nesquena/hermes-webui/pull/4269 github.com: https://github.com/nesquena/hermes-webui/commit/2a3baa71b81ca92da8ece8616a09f15894beec71 vulncheck.com: https://www.vulncheck.com/advisories/hermes-webui-broken-access-control-in-api-session-endpoint
Credits
Chia Min Jun Lennon