Is CVE-2026-86104 being actively exploited?

CVE-2026-86104 is not currently listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.

What is the CVSS score for CVE-2026-86104?

CVE-2026-86104 has a CVSS 3.1 base score of 7.5 (HIGH).

CVE-2026-86104

HIGH · CVSS 7.5EPSS 0.4%EU EUVD

An uncontrolled resource consumption vulnerability in the Fireware OS login process (wgagent) allows a remote, unauthenticated attacker to cause a denial of service by sending a specially crafted request.

Key facts

CVSS score: 7.5 (v3.1)
Severity: HIGH
CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Weakness (CWE): CWE-400
EPSS score: 0.4% (28th percentile)
In CISA KEV: No
In EU EUVD: Yes (EUVD-2026-89501)
Published: September 30, 2026
NVD last modified: October 6, 2026
Status: Analyzed

EU Vulnerability Database (EUVD)

This vulnerability is also tracked by ENISA as EUVD-2026-89501 in the EU Vulnerability Database. Last updated in EUVD on September 30, 2026.

View on the EU Vulnerability Database

Affected products

watchguard / fireware

Certified products that may be affected

1 FIPS 140 or Common Criteria certified product, from automated matching by sec-certs.org.

WatchGuard Fireware OS v12.3.1.B585922 (Running on Firebox Security Appliances) with WatchGuard Dimension 2.1.2.B588050 Software - WatchGuard Technologies Inc. - Common Criteria 2018-26-INF-3091 - archived

References

https://psirt.watchguard.com/CVE-2026-86104(Patch, Vendor Advisory)

Last updated October 8, 2026 · Source: NVD, CISA KEV, FIRST.org EPSS

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