UniFi OS CRLF injection — authentication bypass
A CVSS 10.0 CRLF injection vulnerability in Ubiquiti's UniFi OS allows unauthenticated remote attackers to bypass authentication. Affects UniFi OS devices; patch version not yet publicly documented.
- Vendor
- Ubiquiti
- Product
- UniFi OS (all devices running affected builds)
- CVSS
- 10.0
- EPSS (exploit probability)
- 0.8%
- Status
- patched
- Published
Is CVE-2026-77550 being exploited?
Not on any exploited-vulnerability catalog we track. CVE-2026-77550 was not on the CISA, ENISA or CIRCL exploited catalogs as of our 2026-10-21 snapshot. That can change quickly; check the write-up below for the latest reporting.
FIRST's EPSS model puts the probability of exploitation activity in the next 30 days at 0.8% (scored October 14, 2026).
- CISA KEV[ — ]
- ENISA EUVD (exploited)[ — ]
- CIRCL KEV[ — ]
Catalog snapshot 2026-10-21. Full cross-catalog view: /kev-comparison
CVE-2026-77550 timeline
Every event links to its source. Catalog dates are each catalog's own; day offsets count from NVD publication. Data: JSON
CVE-2026-77550 is a maximum-severity (CVSS 10.0) CRLF injection vulnerability in Ubiquiti’s UniFi OS — the underlying operating system running across UniFi network devices. Exploitation allows unauthenticated remote attackers to bypass authentication. The specific patched OS build version had not been publicly specified in initial disclosure; check the Ubiquiti security advisory bulletin for the definitive version requirement.
No known active exploitation at time of disclosure.
Check your UniFi OS console for available updates and apply the latest UniFi OS build immediately.
Other Ubiquiti CVEs we track
| CVE / Vulnerability | Severity | CVSS | EPSS | Added to KEV |
|---|---|---|---|---|
| CVE-2026-77554 UniFi Talk command injection — unauthenticated remote code executionwrite-up | [ CRITICAL ] | 10.0 | 1.6% | — |
| CVE-2026-77537 UniFi Protect Application improper input validation — unauthenticated RCEwrite-up | [ CRITICAL ] | 10.0 | 1.6% | — |
| CVE-2026-54400 Ubiquiti UniFi Access improper access control (Bulletin 066)write-up | [ CRITICAL ] | 9.1 | 0.5% | — |
| CVE-2026-50748 Ubiquiti UniFi critical flaw (Bulletin 066)write-up | [ CRITICAL ] | 9.9 | 1.6% | — |
| CVE-2026-50747 Ubiquiti UniFi critical flaw (Bulletin 066)write-up | [ CRITICAL ] | 9.9 | 0.5% | — |
| CVE-2026-50746 Ubiquiti UniFi Connect command injection (Bulletin 066)write-up | [ CRITICAL ] | 10.0 | 1.7% | — |
| CVE-2026-34910 Ubiquiti UniFi OS Improper Input Validation Vulnerability | [ CRITICAL ] | 10.0 | 45.8% | |
| CVE-2026-34909 Ubiquiti UniFi OS Path Traversal Vulnerability | [ CRITICAL ] | 10.0 | 1.8% |
