# CVE-2026-77550: Ubiquiti UniFi OS CRLF injection authentication bypass

Source: https://junglewise.ai/threats/cve-2026-77550-ubiquiti-unifi-os-crlf-injection-authentication-bypass  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-08-26. Updated: 2026-09-25  
License: CC BY 4.0 with a link back

CVE-2026-77550 · Severity: critical · CVSS 10 · Published 2026-08-26

UniFi OS is a network management platform used to control and monitor Ubiquiti networking devices. A CRLF (carriage return/line feed) injection vulnerability allows an attacker with network access to bypass authentication mechanisms, potentially gaining unauthorized administrative access to UniFi devices and the systems they protect.

Technologies: [Ubiquiti UniFi OS](https://junglewise.ai/threats/technologies/unifi-os). Vendors: [Ubiquiti](https://junglewise.ai/threats/vendors/ubiquiti).

## Quick answers

**Is CVE-2026-77550 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-77550 being exploited in the wild.

**How severe is CVE-2026-77550?** Critical severity, with a CVSS score of 10, published 26 August 2026.

**Which products and versions are affected?** Ubiquiti UniFi OS.

**Is there a fix for CVE-2026-77550?** No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

**How is CVE-2026-77550 attacked?** It is attacked over the network.

**Am I affected by CVE-2026-77550?** Check whether you run Ubiquiti UniFi OS. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

The vulnerability is an Improper Neutralization of CRLF Sequences (CWE-93) in UniFi OS that fails to properly sanitize input, allowing an attacker to inject carriage return and line feed characters to manipulate protocol-level behavior. An attacker with network access can craft malicious requests to bypass authentication controls without requiring valid credentials. This is a network-based attack vector that could lead to complete compromise of UniFi OS instances and downstream network infrastructure. A patch is expected from Ubiquiti; users should monitor the security advisory bulletin for available remediation.

## Affected products

- Ubiquiti UniFi OS

## Timeline

- 2026-08-26: disclosed

## References

- [https://community.ui.com/releases/Security-Advisory-Bulletin-067/fc4a3488-7c43-4628-8bab-f715e96dbfc9](https://community.ui.com/releases/Security-Advisory-Bulletin-067/fc4a3488-7c43-4628-8bab-f715e96dbfc9)

## Related threats

- [Ubiquiti UniFi OS CRLF injection authentication bypass](https://junglewise.ai/threats/cve-2026-77549-ubiquiti-unifi-os-crlf-injection-authentication-bypass)
- [Ubiquiti UniFi OS active debug code privilege escalation](https://junglewise.ai/threats/cve-2026-77545-ubiquiti-unifi-os-active-debug-code-privilege-escalation)
- [Ubiquiti UniFi OS command injection vulnerability](https://junglewise.ai/threats/cve-2026-77540-ubiquiti-unifi-os-command-injection-vulnerability)
- [Ubiquiti UniFi OS command injection in input validation](https://junglewise.ai/threats/cve-2026-77539-ubiquiti-unifi-os-command-injection-in-input-validation)
- [Ubiquiti UniFi OS privilege escalation in access control](https://junglewise.ai/threats/cve-2026-77536-ubiquiti-unifi-os-privilege-escalation-in-access-control)