CVE-2026-18145

Fireware OS Stack-based Buffer Overflow in spamd Allows Remote Code Execution

At a glance

Severity: HIGH 8.6
EPSS: EPSS 0.39 % · percentile 33 (2026-10-27)
State: PUBLISHED
Published: 2026-09-29
Updated: 2026-10-01
Assigner: WatchGuard
NVD status: Analyzed

Description

A stack-based buffer overflow vulnerability in the spamBlocker (spamd) service of WatchGuard Fireware OS allows an authenticated attacker with administrator privileges to crash the service or potentially execute arbitrary code by sending a specially crafted management request.

Scores

Version	Score	Vector	Scored by
CVSS 4.0	HIGH 8.6	CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N	WatchGuard
CVSS 4.0	HIGH 8.6	CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X	NVD · 5d1c2695-1a31-4499-88ae-e847036fd7e3 (Secondary)
CVSS 3.1	HIGH 7.2	CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H	NVD · nvd@nist.gov (Primary)

Weaknesses (CWE)

CWE-121

European references

ENISA EUVD · EUVD-2026-89500
GCVE · GCVE-0-2026-18145

Affected configurations (NVD CPE)

cpe:2.3:o:watchguard:fireware:*:*:*:*:*:*:*:* ≥ 12.0 < 12.5.21
cpe:2.3:o:watchguard:fireware:*:*:*:*:*:*:*:* ≥ 12.12 < 12.12.3
cpe:2.3:o:watchguard:fireware:*:*:*:*:*:*:*:* ≥ 2025.2 < 2026.2.3
cpe:2.3:o:watchguard:fireware:*:*:*:*:*:*:*:* ≥ 2026.3 < 2026.3.2

Affected products

Product	Versions
WatchGuard · Fireware OS	affected 2026.3 < 2026.3.2 ; affected 2025.0 < 2026.2.3 ; affected 12.0 < 12.12.3
WatchGuard · Fireware OS	affected 12.0 < 12.5.21

References

https://psirt.watchguard.com/CVE-2026-18145

Sources

Source	Licence
CVE List (CVEProject cvelistV5)	CVE Program Terms of Use
EPSS (FIRST.org)	FIRST — attribution requested
ENISA EUVD	ENISA — reproduction authorised, source acknowledged
NVD (NIST) via fkie-cad/nvd-json-data-feeds	Public domain — this product uses data from the NVD API but is not endorsed or certified by the NVD