8.7

CVE-2026-86134: Fireware OS Pre-Authentication NULL Pointer Dereference Allows Remote Denial of Service

Analyzed
Published 30-09-2026Last modified 30-09-2026

Vulnerability summary

CVE-2026-86134 is a high (CVSS 8.7) NULL Pointer Dereference vulnerability in watchguard fireware. EPSS estimates a 0.38% chance of exploitation in the next 30 days, higher than 30.4% of scored vulnerabilities.

Overall risk
35/100
0100
Medium · default modelHow is this calculated?
CVSS score
8.7/10
010
High · v4.0 (CVE.org)
EPSS score
0.38%
0%100%
Low · Change unavailable
KEVNot listedNot listed by any tracked catalog.
RansomwareNot flaggedNo ransomware use recorded.
Public exploits0No public exploits recorded

Timeline

  1. 30-09-2026
    PublishedVulnerability first disclosed.
  2. 30-09-2026
    Last modifiedVulnerability information updated.

Description

A NULL pointer dereference vulnerability in the WatchGuard Fireware OS authentication process allows a remote, unauthenticated attacker to crash the management daemon by sending a specially request to the login interface, resulting in a denial of service.

CVSS metrics

3 scores · 2 sources · 2 versions

EPSS trend

Probability

0.38%

Chance of exploitation in the next 30 days

Percentile

30%

Versus all other CVEs

30-day change

Change unavailable

Change unavailable

30-09-202622-10-2026

Known exploited

Compare KEV catalogs
CISA KEV

Not in the CISA KEV catalog.

ENISA CNW

Not in the ENISA CNW catalog.

CIRCL

Not in the CIRCL catalog.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Watchguard2 products
  • fireware≥ 12.0, < 12.5.21 | ≥ 12.12, < 12.12.3 | ≥ 2025.0, < 2026.2.3 | ≥ 2026.3, < 2026.3.2
  • fireware os≥ 2026.3, < 2026.3.2 | ≥ 2025.0, < 2026.2.3 | ≥ 12.0, < 12.12.3 | ≥ 12.0, < 12.5.21

1 vendor · 2 products

References

1 links