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Heap buffer overflow in WatchGuard Fireware OS authentication service

Priority MEDIUM 42CWE-122Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Attack requirements
Present
Impact type
Code execution
Confidentiality · integrity · availability
High · High · High
Fix status
Fixed

Attack profile from CVSS 4.0 · CNA. Fix status from CNA. Impact type from CWE-122 and the CVSS impact.

Summary

Affected are WatchGuard Fireware OS from 2025.1 before 2026.4, from 12.0 before 12.12.4, and from 12.0 before 12.5.22. A heap-based buffer overflow (CWE-122) in the authentication service lets an attacker who controls or intercepts traffic to the configured Active Directory server cause a denial of service or possibly execute arbitrary code by returning a crafted response. No authentication is required.

Written with Claude Haiku 5.5 from the sources below · 2026-11-04

Description from the CNA

A heap-based buffer overflow vulnerability in the Fireware OS authentication service allows an attacker who controls or intercepts traffic to the configured Active Directory server to create a denial of service condition and potentially execute arbitrary code by returning a specially crafted response.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00419 36th percentileScored 2026-11-07
Fix Fixed Fireware OS (WatchGuard): 2026.4, 12.12.4, 12.5.22

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Total

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
WatchGuardFireware OS2025.1 to before 2026.4; 12.0 to before 12.12.42026.4, 12.12.4Patch availableCNA
WatchGuardFireware OS12.0 to before 12.5.2212.5.22Patch availableCNA
  • Fireware OS VendorWatchGuard Affected 2025.1 to before 2026.4; 12.0 to before 12.12.4 Fixed in 2026.4, 12.12.4 Patch available CNA
  • Fireware OS VendorWatchGuard Affected 12.0 to before 12.5.22 Fixed in 12.5.22 Patch available CNA

CPE names Threatist (inferred) · 1

Inferred from how NVD named this product before; not given by a source.

CPEVersionsRoleVendor
cpe:2.3:o:watchguard:fireware:*:*:*:*:*:*:*:*——WatchGuard
  • cpe:2.3:o:watchguard:fireware:*:*:*:*:*:*:*:* Versions — — ·WatchGuard

Remediation

Fireware OS is fixed in 2026.4, 12.12.4 and 12.5.22, so upgrade to the fixed version for your release line. The sources list no vendor advisory identifiers for these fixes.

Written with Claude Haiku 5.5 from the sources below · 2026-11-04

  • Fix · CNA Fireware OS (WatchGuard) Fixed in 2026.4, 12.12.4
  • Fix · CNA Fireware OS (WatchGuard) Fixed in 12.5.22

Fixed in the same release

Records fixed by the same vendor advisory or release, as the CNA lists them.

  • Release ·

    WatchGuard Fireware OS 12.12.4, 2026.4

    17 records Highest priority Priority MEDIUM 9 MEDIUM, 8 LOW

    Other records, highest priority first

    • TI-2026-81380 Fireware OS FireCluster Daemon Lacks Authentication, Allows Remote Root ActionsPriority MEDIUM 48
    • TI-2026-81377 Stack buffer overflow in WatchGuard Fireware OS SIP proxyPriority MEDIUM 48
    • TI-2026-81386 NULL pointer dereference in WatchGuard Fireware OS management loginPriority MEDIUM 44
  • Release ·

    WatchGuard Fireware OS 12.5.22

    14 records Highest priority Priority MEDIUM 8 MEDIUM, 6 LOW

    Other records, highest priority first

    • TI-2026-81380 Fireware OS FireCluster Daemon Lacks Authentication, Allows Remote Root ActionsPriority MEDIUM 48
    • TI-2026-81377 Stack buffer overflow in WatchGuard Fireware OS SIP proxyPriority MEDIUM 48
    • TI-2026-81386 NULL pointer dereference in WatchGuard Fireware OS management loginPriority MEDIUM 44

Timeline

  1. 2026-10-27 Threatist record created from CVE-2026-112709
  2. 2026-10-27 Alias added: GHSA-9g3h-x65r-8m8p
  3. 2026-11-04 CISA SSVC decision points changed

References

  • TI-2022-09698 On WatchGuard Firebox and XTM appliances, an unauthenticated user can execute arbitrary… KEVCVSS 3.1CRITICAL 9.8
  • TI-2025-13451 WatchGuard Firebox iked Out of Bounds Write Vulnerability KEVCVSS 4.0CRITICAL 9.3
  • TI-2025-08474 WatchGuard Firebox iked Out of Bounds Write Vulnerability KEVCVSS 4.0CRITICAL 9.3
  • TI-2022-07330 WatchGuard Firebox and XTM appliances allow a remote attacker with unprivileged… KEVCVSS 3.1HIGH 8.8
  • TI-2023-19293 A DLL hijacking vulnerability in Panda Security VPN for Windows prior to version v15.14.8… CVSS 3.1MEDIUM 6.5
  • TI-2015-04587 Watchguard XCS 9.2 and 10.0 before build 150522 allow remote authenticated users to… CVSS 2.0MEDIUM 6.5
See all 203 →

Sources