What products are affected by CVE-2026-34908?

CVE-2026-34908 affects Ubiquiti UniFi OS. Refer to the vendor advisory and NVD record for affected versions.

Is there a public exploit for CVE-2026-34908?

Yes. Public exploit code or proof-of-concept has been identified for CVE-2026-34908. This lowers the barrier for exploitation and increases the urgency of patching. Organizations should prioritize remediation immediately.

What is the EPSS score for CVE-2026-34908?

CVE-2026-34908 has an EPSS score of 58.4%, placing it in the 99th percentile. This means it has a 58.4% probability of being exploited in the next 30 days, higher than 99% of all known vulnerabilities. EPSS (Exploit Prediction Scoring System) is maintained by FIRST and uses real-world threat data to estimate exploitation likelihood.

Actively Exploited, CISA KEV

CVE-2026-34908: Ubiquiti UniFi OS Critical Vulnerability

Severity: Critical | CVSS 3.1: 10.0 | Published: 2026-05-22 | KEV Added: 2026-06-23

What is CVE-2026-34908?

A malicious actor with access to the network could exploit an Improper Access Control vulnerability found in UniFi OS devices to make unauthorized changes to the system.

Technical Analysis

Weakness Classification

This vulnerability is classified as CWE-284, Improper Access Control. The software does not properly restrict access to resources, allowing unauthorized users to perform actions or access data.

Attack Vector Breakdown

Attack Vector: Network
Attack Complexity: Low
Privileges Required: None
User Interaction: None
Scope: Changed
Confidentiality: High
Integrity: High
Availability: High

Impact Analysis

This vulnerability is exploitable over the network, meaning any system reachable via the internet or internal network is potentially at risk without physical access. The attack complexity is low, requires no special privileges, and needs no user interaction, making it straightforward to exploit at scale. Successful exploitation can result in full confidentiality breach (complete data disclosure), complete integrity compromise (data modification or code execution), total availability loss (denial of service). Notably, the vulnerability's scope is changed, meaning exploitation can affect resources beyond the vulnerable component, for example, escaping a sandbox or container to impact the host system. The software does not properly restrict access to resources, allowing unauthorized users to perform actions or access data.

Exploitation Probability (EPSS): 58.4% chance of exploitation in the next 30 days (99th percentile). This places the vulnerability in the highest risk tier, immediate action is critical.

Exploit Availability

Public exploit code or proof-of-concept is available for CVE-2026-34908. This significantly increases the risk of exploitation, as attackers can use or adapt existing exploit code rather than developing their own. A public exploit reference has been identified. Organizations should treat this as an urgent patching priority.

Is CVE-2026-34908 being exploited?

Yes. CVE-2026-34908 is listed in CISA's Known Exploited Vulnerabilities (KEV) catalog, restricted to CVEs with confirmed active exploitation in the wild. CISA added this vulnerability on 2026-06-23. Inclusion in KEV triggers the patching mandate under BOD 22-01 for U.S. federal civilian agencies, with a remediation deadline of 2026-06-26. Additionally, public exploit code is available, which lowers the barrier for attackers.

How to fix CVE-2026-34908

Apply the security update issued by Ubiquiti for UniFi OS. If an immediate patch is not possible, consult the vendor advisory for mitigation guidance, restrict network exposure of the affected service, and monitor logs for indicators of exploitation. CISA's Known Exploited Vulnerabilities catalog requires U.S. federal agencies to remediate this vulnerability by the due date shown below under Binding Operational Directive 22-01. Private organizations should treat KEV entries as priority-one patches because active exploitation has been confirmed in the wild.

Related Vulnerabilities

Other actively exploited vulnerabilities affecting UniFi OS or sharing the same weakness (CWE-284):

CVE-2026-34910 (Critical 10.0) [same product], A malicious actor with access to the network could exploit an Improper Input…
CVE-2026-34909 (Critical 10.0) [same product], A malicious actor with access to the network could exploit a Path Traversal…
CVE-2026-48907 (Critical 9.8) [same CWE], A vulnerability in the JCE editor extension for Joomla allows the creation of…
CVE-2026-35616 (Critical 9.8) [same CWE], A improper access control vulnerability in Fortinet FortiClientEMS 7.4.5…
CVE-2025-12480 (Critical 9.1) [same CWE], Triofox versions prior to 16.7.10368.56560, are vulnerable to an Improper…

Frequently asked questions

Is CVE-2026-34908 critical?

CVE-2026-34908 has a CVSS 3.1 base score of 10.0, Critical severity. It should be treated as a priority patch, especially given the active exploitation confirmed by CISA. The availability of public exploit code further increases the urgency.

Is CVE-2026-34908 being actively exploited?

Yes, CISA added CVE-2026-34908 to the Known Exploited Vulnerabilities catalog on 2026-06-23. Inclusion in KEV means CISA has confirmed in-the-wild exploitation. Public exploit code has also been identified, making exploitation accessible to a broader range of threat actors.

How do I patch CVE-2026-34908?

Apply the security update from Ubiquiti for UniFi OS. Federal agencies must remediate by 2026-06-26 under BOD 22-01.

What type of vulnerability is CVE-2026-34908?

CVE-2026-34908 is classified under CWE-284 (Improper Access Control). The software does not properly restrict access to resources, allowing unauthorized users to perform actions or access data.

What is the CVSS score for CVE-2026-34908?

CVE-2026-34908 has a CVSS 3.1 base score of 10.0, classifying it as Critical severity. The attack vector is Network, attack complexity is Low, and no privileges are required.