Exploited Ransomware

CVE-2025-14733

WatchGuard Firebox / XTM (Fireware) · Firewalls, VPNs and remote access

WatchGuard Firebox Out of Bounds Write Vulnerability

At a glance

Exploited. Added to CISA’s catalog of exploited vulnerabilities on December 19, 2025.

Used in ransomware attacks, according to CISA.

Affected product: WatchGuard Firebox / XTM (Fireware) (category Firewalls, VPNs and remote access, indicative classification). Name in CISA’s catalog: WatchGuard Firebox.

What should I do?

Apply the patches or mitigations from WatchGuard; if none are available, stop using the product. For cloud services, follow the guidance from WatchGuard.

Deadline set by CISA for US federal agencies: 7 days (due December 26, 2025). It only binds those agencies, but it is a useful measure of urgency.

WatchGuard security advisories page (general page, not the advisory for this vulnerability)
The vendor’s specific advisory is listed in the NVD references: CVE-2025-14733 on the NVD website.

Original text of the required action (CISA)

Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.

Timeline

December 19, 2025 Vulnerability published Publication date (NVD)
December 19, 2025 Exploitation confirmed Added to CISA’s KEV catalog
December 26, 2025 CISA deadline Remediation deadline set for US federal agencies

The facts, with their sources

Exploitation confirmed: Yes, on December 19, 2025 Date added to the catalog of exploited vulnerabilities. Exploitation itself may have started earlier. Source: KEV catalog, collected September 29, 2026 at 14:57 UTC
Ransomware: Known use Source: KEV catalog, collected September 29, 2026 at 14:57 UTC
Hunt for compromise: Not requested by CISA Source: KEV catalog, collected September 29, 2026 at 14:57 UTC
CISA required action: Apply the patches or mitigations from WatchGuard; if none are available, stop using the product. For cloud services, follow the guidance from WatchGuard. Rewritten by this site from CISA’s original text. Source: KEV catalog, collected September 29, 2026 at 14:57 UTC
CISA deadline: December 26, 2025, 7 days Set for US federal agencies: a measure of urgency, not an obligation elsewhere. Source: KEV catalog, collected September 29, 2026 at 14:57 UTC
Vulnerability published: December 19, 2025 Source: National Vulnerability Database (NVD), collected September 29, 2026 at 15:00 UTC
Product according to CISA: WatchGuard Firebox Filed by this site under “Firewalls, VPNs and remote access” (indicative classification). Source: KEV catalog, collected September 29, 2026 at 14:57 UTC
CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H Technical detail of the score: attack vector, complexity, impact. Source: National Vulnerability Database (NVD), collected September 29, 2026 at 15:00 UTC

Severity and activity

9.8 / 10 CVSS severity: critical

Score from the NVD. Collected Sep 29, 2026.

— Probability of exploitation in the next 30 days (EPSS)

FIRST’s EPSS model. Since exploitation is already confirmed, this figure is mostly useful to compare activity. Collected Sep 29, 2026.

Description

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.

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.

Summary from CISA (KEV catalog).

CERT-FR advisories

No advisory among the latest CERT-FR publications this site follows. That does not mean there are none.

Information reused under the Open Licence 2.0 (Etalab); the date of last update is shown for each advisory. This site is neither affiliated with nor endorsed by ANSSI.

Sources for this page

CISA KEV catalog: exploitation, date added, required action, deadline, ransomware.
NVD (NIST): CVSS severity, publication date, description, vendor references.
EPSS (FIRST): probability of exploitation.
CERT-FR: advisories and alerts (in French).
Brand and category: indicative classification by this site (method).