8.6

CVE-2026-18145: Fireware OS Stack-based Buffer Overflow in spamd Allows Remote Code Execution

Analyzed
Published 29-09-2026Last modified 01-10-2026

Vulnerability summary

CVE-2026-18145 is a high (CVSS 8.6) Stack-based Buffer Overflow vulnerability in watchguard fireware. EPSS estimates a 0.39% chance of exploitation in the next 30 days, higher than 31.8% of scored vulnerabilities.

Overall risk
34/100
0100
Medium · default modelHow is this calculated?
CVSS score
8.6/10
010
High · v4.0 (CVE.org)
EPSS score
0.39%
0%100%
Low · Change unavailable
KEVNot listedNot listed by any tracked catalog.
RansomwareNot flaggedNo ransomware use recorded.
Public exploits0No public exploits recorded

Timeline

  1. 29-09-2026
    PublishedVulnerability first disclosed.
  2. 01-10-2026
    Last modifiedVulnerability information updated.

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.

CVSS metrics

3 scores · 2 sources · 2 versions

EPSS trend

Probability

0.39%

Chance of exploitation in the next 30 days

Percentile

32%

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 | ≥ 2025.2, < 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