Ubiquiti UniFi OS Improper Access Control Vulnerability
CVE-2026-34908 is a critical improper access control flaw in Ubiquiti UniFi OS, affecting UniFi OS Server 5.0.6 and earlier and corresponding vulnerable UniFi OS device releases addressed by Ubiquiti in Security Advisory Bulletin 064. The vendor describes the issue as allowing a malicious actor with network access to make unauthorized changes to the system. Supporting technical analysis indicates this flaw is part of the UniFi OS authentication gateway and can be used with CVE-2026-34909 as an authentication bypass due to inconsistent handling of specially crafted request URIs by NGINX and the underlying authentication logic. Specifically, raw request paths beginning with an auth-exempt prefix can normalize into protected internal routes, allowing access to backend functionality that should require authentication. On its own, the vulnerability enables unauthorized system changes; when chained with the related path traversal and command injection flaws, it can contribute to unauthenticated remote compromise.
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Impact, mitigation & remediation
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Impact
What an attacker gets, and what they’ve been doing with it.
Mitigation
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Remediation
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Exploits
No valid public exploits. Mallory filtered out 1 candidate as fakes, detection scripts, or README-only repos.
All candidate exploits were filtered out by Mallory's validation.
Affected products & vendors
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Recent activity
53 sources tracked across advisories, community write-ups, and news. New activity surfaces here as Mallory finds it.
An improper access control vulnerability in Ubiquiti UniFi OS that allows an unauthenticated attacker with network access to make unauthorized system changes.
An access control bypass/authentication gateway bypass vulnerability in Ubiquiti UniFi OS that can allow unauthenticated access to protected backend services and can be chained toward privileged remote code execution.
An improper input validation vulnerability in Ubiquiti UniFi OS that can allow a malicious actor with network access to conduct command injection. It is part of a three-vulnerability RCE chain.
A critical improper access control vulnerability in Ubiquiti UniFi OS that can allow remote, unauthenticated attackers to make unauthorized changes. Patch analysis indicates it is part of an authentication gateway bypass chain involving crafted NGINX requests.
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Cross-references every affected SKU, including bundled OEM variants.
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