CVE-2026-77549: CWE-93 Improper neutralization of CRLF sequences ('CRLF injection') in Ubiquiti Inc UniFi OS Server
Description
CVE-2026-77549 is a critical vulnerability in Ubiquiti Inc's UniFi OS Server involving improper neutralization of CRLF sequences (CRLF injection). An attacker with network access could exploit this flaw under certain conditions to bypass authentication on affected UniFi OS devices or instances. The vulnerability has a high CVSS score of 9.0, indicating severe impact on confidentiality, integrity, and availability. No official patch or remediation guidance has been provided yet, and no known exploits are reported in the wild.
CVSS v3.1
Score 9.0critical
Affected software
Ubiquiti Inc
UniFi OS Server
Ubiquiti Inc
Cloud Keys
Ubiquiti Inc
Network Video Recorders
Ubiquiti Inc
Enterprise Network Video Recorders
Ubiquiti Inc
Enterprise Network Attached Storage
Ubiquiti Inc
Dream Machines
Ubiquiti Inc
Enterprise Firewall Core
Ubiquiti Inc
Dream Routers
Ubiquiti Inc
Enterprise Fortress Gateway
Ubiquiti Inc
Cloud Gateways
Ubiquiti Inc
Dream Wall
Ubiquiti Inc
Express 7
Ubiquiti Inc
Network Attached Storage
Ubiquiti Inc
Express
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
This vulnerability (CVE-2026-77549) in UniFi OS Server is classified as CWE-93, involving improper neutralization of CRLF sequences. It allows a remote attacker with network access to potentially bypass authentication mechanisms by exploiting CRLF injection under certain conditions. The vulnerability affects UniFi OS devices but specific affected versions are not stated. The CVSS v3.1 score is 9.0 (AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H), reflecting critical impact with high attack complexity and no privileges or user interaction required. No patch or official remediation level has been published by the vendor as of the data provided.
Potential Impact
Successful exploitation could lead to complete compromise of affected UniFi OS devices by bypassing authentication controls, resulting in full confidentiality, integrity, and availability loss. This could allow unauthorized access and control over the device or instance.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until an official fix is released, network-level controls restricting access to UniFi OS devices and monitoring for suspicious activity may help reduce risk. No vendor advisory or official fix is currently available.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- Ubiquiti
- Date Reserved
- 2026-08-20T20:32:37.794Z
- Cvss Version
- 3.1
- State
- PUBLISHED
Threat ID: 6a8ec57dacd9273b49c21781
Added to database: 08/26/2026, 10:52:45 UTC
Last enriched: 09/09/2026, 18:37:19 UTC
Last updated: 10/10/2026, 18:48:22 UTC
Views: 88
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