Is CVE-2026-8247 being actively exploited?

CVE-2026-8247 is not currently listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.

What is the CVSS score for CVE-2026-8247?

CVE-2026-8247 has a CVSS 3.1 base score of 8.8 (HIGH).

CVE-2026-8247

HIGH · CVSS 8.8EPSS 0.4%EU EUVD

An Out-of-bounds Write vulnerability in WatchGuard Fireware OS may allow an unauthenticated attacker on the same local network segment to execute arbitrary code. This vulnerability affects Fireware OS 11.0 up to and including 11.12.4_Update1, 12.0 up to and including 12.12 and 2025.1 up to and including 2026.2.

Key facts

CVSS score: 8.8 (v3.1)
Severity: HIGH
CVSS vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Weakness (CWE): CWE-120
EPSS score: 0.4% (31th percentile)
In CISA KEV: No
In EU EUVD: Yes (EUVD-2026-41459)
Published: July 3, 2026
NVD last modified: August 28, 2026
Status: Analyzed

EU Vulnerability Database (EUVD)

This vulnerability is also tracked by ENISA as EUVD-2026-41459 in the EU Vulnerability Database. Last updated in EUVD on August 27, 2026.

View on the EU Vulnerability Database

Affected products

watchguard / firebox cloud
watchguard / firebox m270
watchguard / firebox m290
watchguard / firebox m295
watchguard / firebox m370
watchguard / firebox m390
watchguard / firebox m395
watchguard / firebox m440
watchguard / firebox m4600
watchguard / firebox m470
watchguard / firebox m4800
watchguard / firebox m495
watchguard / firebox m5600
watchguard / firebox m570
watchguard / firebox m5800
watchguard / firebox m590
watchguard / firebox m595
watchguard / firebox m670
watchguard / firebox m690
watchguard / firebox m695
watchguard / firebox nv5
watchguard / firebox t115-w
watchguard / firebox t125
watchguard / firebox t125-w
watchguard / firebox t145
watchguard / firebox t145-w
watchguard / firebox t15
watchguard / firebox t185
watchguard / firebox t20
watchguard / firebox t25
watchguard / firebox t35
watchguard / firebox t40
watchguard / firebox t45
watchguard / firebox t55
watchguard / firebox t70
watchguard / firebox t80
watchguard / firebox t85
watchguard / fireboxv
watchguard / fireware
watchguard / fireware
watchguard / fireware

Certified products that may be affected

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

WatchGuard Firebox Security Appliances with Fireware v11.11 and WatchGuard Dimension 2.1 - WatchGuard Technologies, Inc. - Common Criteria CSEC2015010 - archived
WatchGuard XTM Firewalls and Fireware XTM Operating System v11.5.1 - WatchGuard Technologies, Inc. - Common Criteria 383-4-160 - archived

References

https://psirt.watchguard.com/CVE-2026-8247(Broken Link)
https://www.watchguard.com/wgrd-psirt/advisory/wgsa-2026-00026(Vendor Advisory)

Last updated September 17, 2026 · Source: NVD, CISA KEV, FIRST.org EPSS

Query CVEs from your AI assistant

The CVE/NVD Explorer brain answers CVE questions directly inside Claude, ChatGPT, or any MCP assistant — always up to date, no setup. Add it once and stop pasting advisories into chat.

Add the CVE brain