Hermes WebUI < 0.51.443 - Broken Access Control in /api/session Endpoint (CVE-2026-55197) | HOL Guard CVE

Unknown severity · Source severity not reportedCVE-2026-55197

Hermes WebUI < 0.51.443 - Broken Access Control in /api/session Endpoint

Answer in brief

CVE-2026-55197 records a Unknown severity vulnerability in Hermes WebUI < 0.51.443 - Broken Access Control in /api/session Endpoint. The current sources do not mark it as known exploited. The current feed maps nesquena/hermes-webui (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Jun 17, 2026Updated Sep 17, 2026Source checked Sep 17, 2026First seen by HOL Sep 17, 2026Material review Sep 17, 2026

Upstream Advisory

Key facts

Risk: Unknown severitySource severity not reported
Exploitation: Not marked as known exploited
Affected software: 1 mapped package or product
Fix availability: Available

Why this deserves its current priority

A CVSS score is not reported in the current record. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps nesquena/hermes-webui (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
nesquena/hermes-webuigeneric	>=0 <0.51.443	0.51.443

Recommended response

Check inventory. Check lockfiles and deployed manifests for nesquena/hermes-webui.
Review the reported fix. Update nesquena/hermes-webui to 0.51.443 if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

Published upstream
Jun 17, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Sep 17, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Sep 17, 2026

Sources and claim methodology

Upstream source description

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.

Quoted source text, attributed separately from HOL analysis.