CVE-2026-58123
Unauthenticated RCE in Hermes WebUI via embedded terminal API endpoints.
Is CVE-2026-58123 being exploited?
Not confirmed. CVE-2026-58123 does not appear in CISA's Known Exploited Vulnerabilities catalog, which records only exploitation that has been observed and reported publicly. That is evidence of absence of a report, not evidence the flaw is unattacked. EPSS currently estimates a 4.6% probability of exploitation in the next 30 days.
How severe is CVE-2026-58123?
CVE-2026-58123 is rated Critical with a CVSS score of 9.3. Severity describes how bad exploitation would be, not how likely it is: pair it with exploitation evidence before deciding what to patch first.
Is there a patch for CVE-2026-58123?
Yes. A fix has been recorded for CVE-2026-58123. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-58123 affect?
CVE-2026-58123 affects Hermes WebUI < 0.51.788, Servers running Hermes WebUI (embedded terminal API). Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-58123?
Upgrade Hermes WebUI to >=0.51.788; restrict/disable UI terminal endpoints and block access until patched.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Attacker can create a session, attach a PTY, and execute arbitrary shell commands as the web server process via unauthenticated HTTP requests.
Immediate action required
- affected< 0.51.788
As published in the CVE Program record. A version outside these ranges is not a statement that it is unaffected — vendors sometimes understate a range, and distribution-backported builds carry upstream numbers that do not reflect what was patched into them.