CVE-2026-54400
Privilege escalation via improper access control in UniFi Access Application
Is CVE-2026-54400 being exploited?
Not confirmed. CVE-2026-54400 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 0.52% probability of exploitation in the next 30 days.
How severe is CVE-2026-54400?
CVE-2026-54400 is rated Critical with a CVSS score of 9.1. 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-2026-54400?
Yes. A fix has been recorded for CVE-2026-54400. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-54400 affect?
CVE-2026-54400 affects UniFi Access Application, Host devices running UniFi Access Application. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-54400?
Limit access to management interface; monitor activity; patch when released
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Network attacker with high privileges can escalate to the host OS via improper access control in UniFi Access Application.
Immediate action required
- affected< 4.2.29
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.