---
title: "CVE-2025-9242: WatchGuard Firebox Out-of-Bounds Write Vulnerability"
url: https://erroneo.us/security/cve/CVE-2025-9242/
description: "CVE-2025-9242 (WatchGuard Firebox): Exploited in the wild (CISA KEV). An Out-of-bounds Write vulnerability in the WatchGuard Fireware OS iked process may…"
type: vulnerability-record
section: "Security Digest"
date_published: 2025-09-17
date_modified: 2026-08-10
publisher: erroneo.us
author: erroneo.us Security Desk
cve: "CVE-2025-9242"
kev: true
cvss: 9.3
epss: 0.91804
license: All rights reserved. Quote with attribution and a link.
---

# CVE-2025-9242: WatchGuard Firebox Out-of-Bounds Write Vulnerability

**Signal:** Exploited: patch now if you run it. CISA has confirmed exploitation in the wild. (Computed from CISA KEV, EPSS and CVSS; not an editorial verdict.)

## Should you act?

- Yes, if you run WatchGuard Firebox. CISA added this CVE to its Known Exploited Vulnerabilities catalog on 2025-11-12, which means there is reliable evidence of exploitation in the wild. US federal agencies must remediate by 2025-12-03 ; treat that as the outer limit, not the target.
- EPSS 91.8% , percentile 99.8: FIRST’s model estimates a 91.8% chance of exploitation activity in the next 30 days, higher than 99.8% of all scored CVEs (very high). EPSS is a probability, not a verdict.
- Remotely reachable with no login and no user interaction. If the vulnerable service is exposed to the internet, prioritize it.

## What it is

An Out-of-bounds Write vulnerability in the WatchGuard Fireware OS iked process 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. If the Firebox was previously configured with the mobile user VPN with IKEv2 or a branch office VPN using IKEv2 to a dynamic gateway peer, and both of those configurations have since been deleted, that Firebox may still be vulnerable if a branch office VPN to a static gateway peer is still configured.

## Affected products (CVE record)

- WatchGuard Fireware OS: 11.0 <= 11.12.4+541730, 12.0 < 12.11.4, 2025.0 < 2025.1.1
- WatchGuard Fireware OS: 12.0 < 12.3.1+722811
- WatchGuard Fireware OS: 12.0 < 12.5.13

## Severity

- WatchGuard CVSS 4.0: 9.3 `CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N`

## Exploitation

- CISA KEV: added 2025-11-12; federal due date 2025-12-03. Known ransomware use: Unknown.
- CISA required action: Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
- CISA SSVC assessment: exploitation active , automatable yes , technical impact total .
- FIRST EPSS (model of 2026-10-21): 91.80% probability of exploitation activity in the next 30 days; percentile 99.8.

## Sources

- [psirt.watchguard.com](https://psirt.watchguard.com/CVE-2025-9242)
- [watchguard.com](https://www.watchguard.com/wgrd-psirt/advisory/wgsa-2025-00015)
- [CVE.org record CVE-2025-9242](https://www.cve.org/CVERecord?id=CVE-2025-9242)
- [NVD entry CVE-2025-9242](https://nvd.nist.gov/vuln/detail/CVE-2025-9242)
- [CISA Known Exploited Vulnerabilities catalog entry](https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2025-9242)
- [github.com](https://github.com/watchtowrlabs/watchTowr-vs-WatchGuard-CVE-2025-9242/blob/main/watchTowr-vs-WatchGuard-CVE-2025-9242.py)

---
Source page: https://erroneo.us/security/cve/CVE-2025-9242/ · Security Digest: https://erroneo.us/security/ · More: https://erroneo.us/llms.txt