CVE-2026-55198CWE-639

CVE-2026-55198

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 an authorization bypass vulnerability in the session export endpoint that allows authenticated users to access sessions from other profiles. The _handle_session_export handler in api/routes.py fails to verify active-profile ownership before serializing session data, enabling attackers to exfiltrate foreign session transcripts by guessing or knowing session identifiers.

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/3991 · [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-cross-profile-session-data-exfiltration-via-session-export-endpoint · [email protected]https://github.com/nesquena/hermes-webui/pull/3991 · 134c704f-9b21-4f2e-91b3-4a467353bcc0
EPSS history
Timeline
  • 17 JUN 17:59Z
    Hermes WebUI < 0.51.443 - Cross-Profile Session Data Exfiltration via Session Export Endpoint
    cvelistv5