Authentication bypass via CRLF injection
Published Aug 26, 2026 · Updated Aug 27, 2026
CRLF injection in Ubiquiti UniFi OS allows remote attackers with network access to bypass authentication under certain conditions. Ubiquiti identifies improper neutralization of CRLF sequences but has not disclosed the request field, parser, or authentication decision that mishandles injected delimiters. Exploitation requires network reachability and high-complexity conditions; successful attacks cross the authentication boundary and compromise confidentiality, integrity, and availability.
Summary
What happened
CRLF injection in Ubiquiti UniFi OS allows remote attackers with network access to bypass authentication under certain conditions. Ubiquiti identifies improper neutralization of CRLF sequences but has not disclosed the request field, parser, or authentication decision that mishandles injected delimiters. Exploitation requires network reachability and high-complexity conditions; successful attacks cross the authentication boundary and compromise confidentiality, integrity, and availability.
The record
- CVE
- CVE-2026-77549
- Published
- Aug 26, 2026
- Updated
- Aug 27, 2026
- Vendor
- Ubiquiti Inc.
- Product
- UniFi Cloud Keys
- Classifications
- CWE-93, T1190
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Aug 26, 2026CVE publishedPublication date reported by the CVE source.
- Aug 27, 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=0 <5.1.31
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
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
No public exploit references are available in this record.
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Technologies
Your stack
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Your stack
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