Quick answers
- Is CVE-2026-77558 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-77558 being exploited in the wild.
- How severe is CVE-2026-77558?
- High severity, with a CVSS score of 7.5, published 22 September 2026.
- Which products and versions are affected?
- Ubiquiti UniFi Gateway certain versions.
- Is there a fix for CVE-2026-77558?
- No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.
- How is CVE-2026-77558 attacked?
- It is attacked over the network, in a network appliance.
- Am I affected by CVE-2026-77558?
- Check whether you run Ubiquiti UniFi Gateway at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.
Technical details
An out-of-bounds read vulnerability in UniFi Gateway devices allows a network-adjacent attacker to trigger a denial of service condition. The vulnerability is exploitable by a malicious actor with network access to the device, without requiring authentication or user interaction. Successful exploitation results in a crash or unavailability of the gateway.
Affected products
- Ubiquiti UniFi Gateway certain versions
Timeline
- 2026-09-22: disclosed