An Authentication Bypass vulnerability on UniFi Protect Application with Auto-Adopt Bridge Devices enabled could allow a malicious actor wit

Versions reported by the vendor

Affected version ranges reported by the assigning authority (hackerone). Independent of NVD's CPE analysis and usually ahead of it.

• Ubiquiti Inc UniFi Protect Application

  • 5.2.49 and later · before 5.2.49affected · semver

Other highest-scoring records for the same primary product.

• CVE-2026-77537A malicious actor with access to the network could exploit an Improper Input Validation vulnerability found in UniFi Protect Application to
  40Plan
• CVE-2026-77548A malicious actor with access to the network and low privileges could exploit an Improper Input Validation vulnerability found in UniFi Prot
  39Monitor
• CVE-2026-77533A malicious actor with access to the network and low privileges could exploit an Improper Input Validation vulnerability found in UniFi Prot
  39Monitor
• CVE-2025-23164A misconfigured access token mechanism in the Unifi Protect Application (Version 5.3.41 and earlier) could permit the recipient of a "Share
  17Monitor

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Root cause

Authentication is added route by route instead of being enforced in one place. When a route added later bypasses the shared middleware, the session check never runs for it.

A representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.

1app.use("/admin", requireSession, adminRouter);2
3// Route added later skips the middleware4app.post("/admin-api/config", updateConfig);

1const admin = express.Router();2admin.use(requireSession, requireRole("admin"));3
4admin.post("/config", updateConfig);5app.use("/admin", admin);

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.