CVE-2025-9242 — WatchGuard Firebox Out-of-Bounds Write Vulnerability

An Out-of-bounds Write vulnerability in WatchGuard Fireware OS may allow a remote unauthenticated attacker to execute arbitrary code. This vulnerability affects both the Mobile User VPN with IKEv2 and the Branch Office VPN using IKEv2 when configured with a dynamic gateway peer.T

01What is this vulnerability?

An Out-of-bounds Write vulnerability in WatchGuard Fireware OS may allow a remote unauthenticated attacker to execute arbitrary code. This vulnerability affects both the Mobile User VPN with IKEv2 and the Branch Office VPN using IKEv2 when configured with a dynamic gateway peer.This vulnerability affects Fireware OS 11.10.2 up to and including 11.12.4_Update1, 12.0 up to and including 12.11.3 and…

02Affected products

03Active exploitation status

Yes — actively exploited. Added to the CISA KEV catalog on 2025-11-12. Ransomware use: Unknown.

04Recommended remediation

• Patch to a fixed version listed in the vendor advisory (see references below).
• Mitigate with WAF rules, network egress filters, or feature flags where the patch is not yet available.
• Hunt historical logs for exploitation indicators — see Detection signatures below.

05Technical details

For the full vendor write-up, exploit chains, and reference implementations, see the references list in section 09.

06Detection signatures

Open the Sigma generator with a pre-filled prompt for this CVE to draft a starting detection in your stack of choice:

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07Related CVEs

No directly-cited follow-up CVEs in the KB record for this advisory. The references list in section 09 carries the vendor cross-references.

08Timeline

• Published: 2025-09-17T07:29:23.738Z
• Last modified: 2026-02-26T17:48:28.750Z
• Added to CISA KEV: 2025-11-12
• BOD 22-01 due: 2025-12-03

09References

• www.watchguard.com — https://www.watchguard.com/wgrd-psirt/advisory/wgsa-2025-00015