Service restart via malformed WebSocket headers
Published Jan 5, 2026 · Updated Jan 5, 2026
Memory-buffer overflow in Ubiquiti UniFi Protect Application 6.1.79 through 6.2.71 allows attackers to restart it via adjacent-network traffic. The discovery protocol's WebSocket-header parser fails to validate user-supplied header data, raising an uncaught exception that terminates the application. No authentication or user interaction is required, but the attacker must reach the adjacent network; the demonstrated consequence is a service restart.
Summary
What happened
Memory-buffer overflow in Ubiquiti UniFi Protect Application 6.1.79 through 6.2.71 allows attackers to restart it via adjacent-network traffic. The discovery protocol's WebSocket-header parser fails to validate user-supplied header data, raising an uncaught exception that terminates the application. No authentication or user interaction is required, but the attacker must reach the adjacent network; the demonstrated consequence is a service restart.
The record
- CVE
- CVE-2026-21634
- Published
- Jan 5, 2026
- Updated
- Jan 5, 2026
- Vendor
- Ubiquiti Inc.
- Product
- UniFi Protect Application
- Classifications
- CWE-119, T1499.004
- Attack vector
- adjacent
- Privileges
- unauthenticated
Timeline
How it unfolded
- Jan 5, 2026CVE publishedPublication date reported by the CVE source.
- Jan 5, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=6.1.79 <6.2.72
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
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Weakness, pattern, technique
Public exploit references
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Technologies
Your stack
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Your stack
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