Widely deployed UniFi OS devices; critical access control flaw enabling remote changes, disrupting networks.
CVE-2026-55116
Improper access control in UniFi OS enables unauthorized changes over network.
Is CVE-2026-55116 being exploited?
Not confirmed. CVE-2026-55116 does not appear in CISA's Known Exploited Vulnerabilities catalog, which records only exploitation that has been observed and reported publicly. That is evidence of absence of a report, not evidence the flaw is unattacked. EPSS currently estimates a 0.41% probability of exploitation in the next 30 days.
How severe is CVE-2026-55116?
CVE-2026-55116 is rated Critical with a CVSS score of 9.0. Severity describes how bad exploitation would be, not how likely it is: pair it with exploitation evidence before deciding what to patch first.
Is there a patch for CVE-2026-55116?
Yes. A fix has been recorded for CVE-2026-55116. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-55116 affect?
CVE-2026-55116 affects UniFi OS devices. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-55116?
Monitor advisories; patch when available.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Remote unauthorized config changes on UniFi OS devices via network access; risk of device takeover.
Monitor only
- affected< 5.1.19
- affected< 5.1.19
- affected< 5.1.19
- affected< 5.1.19
- affected< 5.1.19
- affected< 5.1.19
- affected< 5.1.19
As published in the CVE Program record. A version outside these ranges is not a statement that it is unaffected — vendors sometimes understate a range, and distribution-backported builds carry upstream numbers that do not reflect what was patched into them.