Cross-profile session disclosure via unchecked export
Published Jun 17, 2026 · Updated Jun 17, 2026
Authorization bypass in Hermes WebUI before 0.51.443 allows remote authenticated users to read cross-profile session transcripts. The _handle_session_export handler in api/routes.py loads a session by user-controlled identifier and serializes it without comparing its profile to the active profile. Access requires a valid account plus a stale, leaked, guessed, or otherwise known foreign session identifier; disclosure is limited to the redacted transcript and metadata export.
Summary
What happened
Authorization bypass in Hermes WebUI before 0.51.443 allows remote authenticated users to read cross-profile session transcripts. The _handle_session_export handler in api/routes.py loads a session by user-controlled identifier and serializes it without comparing its profile to the active profile. Access requires a valid account plus a stale, leaked, guessed, or otherwise known foreign session identifier; disclosure is limited to the redacted transcript and metadata export.
The record
- CVE
- CVE-2026-55198
- Published
- Jun 17, 2026
- Updated
- Jun 17, 2026
- Vendor
- Nathan Esquenazi
- Product
- Hermes WebUI
- Classifications
- CWE-639, T1213
- Attack vector
- network
- Privileges
- authenticated
Timeline
How it unfolded
- Jun 17, 2026CVE publishedPublication date reported by the CVE source.
- Jun 17, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=0 <0.51.443
What conditions does exploitation require?
What is affected?
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
- Cross-profile session export safe reproductionproof of concept · demonstrated
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Technologies
Your stack
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Your stack
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