CVE-2026-55197: nesquena hermes-webui · Insecure Direct Object Reference
Affects nesquena hermes-webuiSource CVE Database V5
Not known to be exploited · CVSS 7.1 High : upgrade to 0.51.443 soon.
Data as of 30 Oct 2026, 20:25 UTC
- EPSS
- 0.3% chance of exploitation in 30 days – higher than 28% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 0.51.443
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:NExploitation evidence
Disclosed: evidence found.
CVE published 17 Jun 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 30 Oct 2026.
What to do
Upgrade nesquena hermes-webui to 0.51.443.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| nesquenahermes-webui | Affected
| Fixed in
|
GitHubhermes-webuipkg:github/hermes-webuiOther threats | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
Since the vulnerability affects versions before 0.51.443, upgrading to version 0.51.443 or later may address the issue if an official fix is released. Until then, restrict access to the /api/session endpoint and monitor for suspicious activity involving session_id parameters.
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.
References
- github.com/nesquena/hermes-webui/releases/tag/v0.51.443 (opens in a new tab)
- github.com/nesquena/hermes-webui/pull/3982 (opens in a new tab)
- github.com/nesquena/hermes-webui/pull/4269 (opens in a new tab)
- github.com/nesquena/hermes-webui/commit/2a3baa71b81ca92da8ece8616a09f15894beec71 (opens in a new tab)
- vulncheck.com/advisories/hermes-webui-broken-access-control-in-api-session-endpoint (opens in a new tab)