CVE-2025-14733: WatchGuard Firebox Out of Bounds Write Vulnerability

Should you act?

Exploited: patch now if you run it

CISA has confirmed exploitation in the wild. This signal is computed from CISA KEV, EPSS and CVSS data; it is not an editorial verdict.

• Yes, if you run WatchGuard Firebox. CISA added this CVE to its Known Exploited Vulnerabilities catalog on 2025-12-19, which means there is reliable evidence of exploitation in the wild. US federal agencies must remediate by 2025-12-26; treat that as the outer limit, not the target. CISA also lists it as known to be used in ransomware campaigns.
• EPSS 26.5%, percentile 98: FIRST’s model estimates a 26.5% chance of exploitation activity in the next 30 days, higher than 98% 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.

CISA’s summary

WatchGuard Fireware OS iked process contains an out of bounds write vulnerability in the OS iked process. This vulnerability may allow a remote unauthenticated attacker to execute arbitrary code and affects both the mobile user VPN with IKEv2 and the branch office VPN using IKEv2 when configured with a dynamic gateway peer.

Weakness type: CWE-787.

Product: WatchGuard Firebox · Assigned by: WatchGuard · Published: 2025-12-19

Affected and fixed versions

Severity scores

• Attack vector: network (remotely reachable)
• Attack complexity: low
• Attack requirements: none
• Privileges required: none (no login)
• User interaction: none

CVSS measures how bad a flaw is if exploited, not how likely exploitation is. Read it next to the exploitation data below.

Exploitation and urgency

• CISA KEV: added 2025-12-19; federal due date 2025-12-26. Known ransomware use: Known.
• 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): 26.51% probability of exploitation activity in the next 30 days; percentile 98.

Timeline

• 2025-12-19 — Added to CISA’s Known Exploited Vulnerabilities catalog
• 2025-12-19 — CVE record published by WatchGuard
• 2025-12-26 — CISA remediation deadline for US federal agencies
• 2026-09-09 — CVE record last updated

Sources and references

Original sources first. Version and fix details should always be confirmed against the vendor or project advisory.

Vendor and project advisories, patches

1. psirt.watchguard.com psirt.watchguard.com
2. watchguard.com watchguard.com

Vulnerability records

1. CVE.org record CVE-2025-14733 cve.org
2. NVD entry CVE-2025-14733 nvd.nist.gov

Government

1. CISA Known Exploited Vulnerabilities catalog entry cisa.gov

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