CVE-2026-55197CWE-639

CVE-2026-55197

Medium · published June 17, 2026

CVSS v3.1
6.5
EPSS
0%
Percentile
40.0
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS v3.1
6.5 · MEDIUM
Vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
CVSS v4.0
Not supplied
EPSS
0.00474 · 40.0th percentile
Weakness
CWE-639 · Authorization Bypass Through User-Controlled Key
Published
2026-06-17T23:18Z
References (6)
https://github.com/nesquena/hermes-webui/commit/2a3baa71b81ca92da8ece8616a09f15894beec71 · [email protected]https://github.com/nesquena/hermes-webui/pull/3982 · [email protected]https://github.com/nesquena/hermes-webui/pull/4269 · [email protected]https://github.com/nesquena/hermes-webui/releases/tag/v0.51.443 · [email protected]https://www.vulncheck.com/advisories/hermes-webui-broken-access-control-in-api-session-endpoint · [email protected]https://github.com/nesquena/hermes-webui/pull/3982 · 134c704f-9b21-4f2e-91b3-4a467353bcc0
EPSS history
Timeline
  • 17 JUN 17:59Z
    Hermes WebUI < 0.51.443 - Broken Access Control in /api/session Endpoint
    cvelistv5