Exploited CVEs / CVE-2026-34909
CVE-2026-34909
Ubiquiti UniFi OS Path Traversal Vulnerability. Exploitation in the wild is confirmed by CISA, not predicted. Federal agencies were required to remediate by 2026-06-26 (that deadline has passed); treat that date as the outer bound for your own environment. Check the vendor security advisory for the fix.
Risk summary
Actively exploited Ubiquiti UniFi OS vulnerability, Critical severity, CVSS v3 10.0. Added to the CISA KEV catalog 2026-06-23.
Senserva AI Opinion for CVE-2026-34909
One of three UniFi OS vulnerabilities added to the KEV catalog together on 2026-06-23, this path traversal lets a network attacker read files on the underlying system and pivot to an account takeover. It is rated Critical at CVSS 10.0, and attackers commonly chain it with the companion command injection and access control flaws disclosed the same day. Any UniFi console reachable from user VLANs or the internet is exposed.
Do this: Apply the same UniFi OS update that fixes the 2026-06-23 trio and audit local console accounts for changes you did not make.
AI-generated from public data, 2026-07-07. Verify against the vendor advisory before acting.
Senserva AI Opinion and rich prompt for CVE-2026-34909
Copy this prompt into Claude, ChatGPT, or Copilot. The facts are included, sourced from this page.
Updated August 19, 2026. Data refreshed on every build from MSRC, CISA KEV, and FIRST EPSS.
Full tracking and change history for CVE-2026-34909
- Published
- 2026-06-23
- Last revised
- 2026-06-23
- Changes tracked
- 1
Published and last-revised dates are authoritative, from Microsoft MSRC (or the CISA KEV date-added). Senserva additionally records day-to-day changes from 2026-07-07, refreshed several times a day; the change count reflects that forward-only tracking.
The strongest signal is CVE-2026-34909's addition to the CISA KEV catalog on 2026-06-23, confirming active exploitation. Severity was later scored at 10.0 on 2026-07-17, when EPSS began at 2.3%. EPSS then climbed sharply to 56.9% on 2026-07-24 and settled at 63.9% by 2026-08-10, so exploitation likelihood is rising. Prioritize remediation today.
Drawn by Senserva Vivid from the Senserva change record. Hover any point for its date and value.
- 2026-06-23 added to the CISA KEV catalog by CISA
- 2026-07-17 CVSS 0.0 to 10.0; EPSS first scored at 2.3%
- 2026-07-24 EPSS 2.3% to 56.9%
- 2026-08-02 EPSS 56.9% to 62.8%
- 2026-08-10 EPSS 62.8% to 63.9%
Recorded by Senserva on the dates shown, from CISA KEV and FIRST EPSS. This is what moved and when, which neither the vendor advisory nor NVD publishes.
CISA required action
Federal (BOD 22-01) remediation due date: 2026-06-26 (past due).
Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines.
Official fix for CVE-2026-34909
Check the vendor's security advisory channel for the patched UniFi OS versions and workarounds.
Common questions about CVE-2026-34909
Is CVE-2026-34909 actively exploited?
Yes. CVE-2026-34909 was added to the CISA Known Exploited Vulnerabilities (KEV) catalog on 2026-06-23, which means exploitation in the wild has been confirmed, not predicted. Its EPSS 30-day exploitation probability is 64%.
What is the CISA deadline and required action for CVE-2026-34909?
CISA set the federal (BOD 22-01) remediation due date at 2026-06-26, which has passed; treat any unremediated system as overdue. The verbatim required action: Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines.
What fixes CVE-2026-34909?
Check the vendor's security advisory for the patched UniFi OS versions and any workarounds. KEV listing makes this a fix-first item: patch it ahead of higher-CVSS issues nobody is exploiting.
Can I ask my own AI about CVE-2026-34909?
Yes. This page includes a free, ready-to-paste AI prompt containing CVE-2026-34909's key facts: severity, CVSS, EPSS, the KEV date, the CISA due date, and the required action. Copy it into Claude, ChatGPT, or Copilot; the data is refreshed twice a day (5 AM and 3 PM US Central).
Scope and sources
- More exploited Ubiquiti CVEs
- Authoritative references
Every actively exploited CVE, searchable with due dates and CSV export: the exploited-CVE tracker. The newest additions: exploited this week.