PatchSiren

PatchSiren cyber security CVE debrief

CVE-2026-8247 WatchGuard CVE debrief

An Out-of-bounds Write vulnerability in WatchGuard Fireware OS may allow an unauthenticated attacker on the same local network segment to execute arbitrary code. This vulnerability affects Fireware OS 11.0 up to and including 11.12.4_Update1, 12.0 up to and including 12.12 and 2025.1 up to and including 2026.2. The vulnerability has a high severity score and could lead to significant impact if exploited.

Vendor
WatchGuard
Product
Fireware OS
CVSS
HIGH 7.7
CISA KEV
Not listed in stored evidence
Original CVE published
2026-07-03
Original CVE updated
2026-07-07
Advisory published
2026-07-03
Advisory updated
2026-07-07

Who should care

Users of WatchGuard Fireware OS 11.0 through 11.12.4_Update1, 12.0 through 12.12, and 2025.1 through 2026.2 should apply patches or mitigations as recommended by the vendor. This includes administrators and security teams responsible for managing and securing WatchGuard Fireware OS deployments.

Technical summary

The vulnerability is an Out-of-bounds Write issue in WatchGuard Fireware OS. An unauthenticated attacker on the same local network segment could exploit this to execute arbitrary code. Affected versions include Fireware OS 11.0 up to 11.12.4_Update1, 12.0 up to 12.12, and 2025.1 up to 2026.2. The vulnerability has a CVSS score of 7.7 and is classified as HIGH severity. This issue requires immediate attention as it could lead to significant impact if exploited, including arbitrary code execution. Users of affected versions should prioritize patching or applying recommended mitigations. The CVE record and NVD entry provide further details, but verification with WatchGuard is recommended for precise guidance.

Defensive priority

High due to the potential for arbitrary code execution by an unauthenticated attacker on the local network segment.

Recommended defensive actions

  • Apply patches or updates provided by WatchGuard for Fireware OS versions 11.0 through 11.12.4_Update1, 12.0 through 12.12, and 2025.1 through 2026.2.
  • Implement network segmentation to limit the attack surface.
  • Monitor network traffic for suspicious activity.
  • Consider using compensating controls such as intrusion detection/prevention systems.
  • Review and update asset inventory to identify potentially affected systems.
  • Track exceptions and retest remediated assets to ensure successful patching.

Evidence notes

The CVE record was published on 2026-07-03T00:16:52.773Z and was last modified on 2026-07-07T05:16:55.517Z. The NVD entry is currently Awaiting Analysis. This information is based on the CVE record and NVD entry. Further verification is recommended to confirm affected scope and vendor guidance.

Official resources

AI-assisted PatchSiren debrief based on the supplied source corpus. The CVE record was published on 2026-07-03T00:16:52.773Z and has not been modified since then. The NVD entry is currently Awaiting Analysis.