Quick answers
- Is CVE-2026-93862 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-93862 being exploited in the wild.
- How severe is CVE-2026-93862?
- Informational severity, published 27 October 2026.
- Which products and versions are affected?
- Watchguard Fireware OS 2025.1 to 2026.3, 12.0 to 12.12.3 (Default and T15/T35 with different ranges).
- Is there a fix for CVE-2026-93862?
- Yes: fixed in Fireware OS 2026.4, 12.12.4, 12.5.22. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
- How is CVE-2026-93862 attacked?
- It is attacked over the network or from the adjacent network.
- Am I affected by CVE-2026-93862?
- Check whether you run Watchguard Fireware OS 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.
How to fix
- Fixed in: Fireware OS 2026.4, 12.12.4, 12.5.22
Technical details
An out-of-bounds read in FireCluster Sync processing (CWE-125, CWE-129, CWE-787, CWE-823) allows an attacker on the cluster interconnect—such as a compromised cluster peer or on-path network attacker—to send specially crafted network traffic that triggers the vulnerability. Exploitation results in repeated crashes of the cluster synchronization process, achieving sustained denial of service. A fix is available in Fireware OS 2026.4, 12.12.4, and 12.5.22.
Affected products
- WatchGuard Fireware OS 2025.1 to 2026.3, 12.0 to 12.12.3 (Default and T15/T35 with different ranges)
Timeline
- 2026-10-27: disclosed
- 2026-10-27: advisory