4.8

CVE-2026-13376: watchguard fireware Cross-site Scripting

CVSS: 4.8v4.0MediumModified
Published 02-07-2026Last modified 27-08-2026
Open JSON

Vulnerability summary

CVE-2026-13376 is a medium (CVSS 4.8) Cross-site Scripting vulnerability in watchguard fireware. EPSS estimates a 0.27% chance of exploitation in the next 30 days, higher than 18.2% of scored vulnerabilities.

Overall risk
19/100
0100
Low · default modelHow is this calculated?
CVSS score
4.8/10
010
Medium · v4.0 (CVE.org)
EPSS score
0.27%
0%100%
Low · 0.00 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Timeline

  1. 02-07-2026
    PublishedVulnerability first disclosed.
  2. 27-08-2026
    Last modifiedVulnerability information updated.

Description

Improper Neutralization of Input During Web Page Generation (XSS or 'Cross-site Scripting') vulnerability in WatchGuard Fireware OS spamBlocker module allows Stored XSS. This vulnerability is an additional unmitigated attack path for CVE-2025-1071. This issue affects Fireware OS 12.0 up to and including 12.12, 12.5 up to and including 12.5.18, and 2025.1 up to and including 2026.2.

CVSS metrics

3 scores · 2 sources · 2 versions

EPSS trend

Probability

0.27%

Chance of exploitation in the next 30 days

Percentile

18%

Versus all other CVEs

30-day change

0.00 pp

From 0.27% on 21-09-2026

21-09-202621-10-2026
EPSS score
0.27%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Watchguard2 products
  • fireware≥ 12.0, < 12.12.1 | ≥ 2025.1, < 2026.2.1 | ≥ 12.5, ≤ 12.5.18
  • fireware os≥ 2025.1, < 2026.2.1 | ≥ 12.0, < 12.12.1 | ≥ 12.0, < 12.11.9 | ≥ 12.0, < 12.5.19

1 vendor · 2 products

References

2 links