Answer in brief
CVE-2026-3987 records a Unknown severity vulnerability in WatchGuard Firebox Arbitrary File Write vis Path Traversal in Fireware Web UI. The current sources do not mark it as known exploited. The current feed maps WatchGuard/Fireware OS (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
A CVSS score is not reported in the current record. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps WatchGuard/Fireware OS (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| WatchGuard/Fireware OSgeneric | >=2025.1 <2026.2 || >=12.6.1 <12.12 | 2026.2, 12.12 |
Published upstream
Apr 1, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Aug 10, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Aug 10, 2026
A path traversal vulnerability in the Fireware OS Web UI on WatchGuard Firebox systems may allow a privileged authenticated remote attacker to execute arbitrary code in the context of an elevated system process.
Quoted source text, attributed separately from HOL analysis.
Answer in brief
CVE-2026-3987 records a Unknown severity vulnerability in WatchGuard Firebox Arbitrary File Write vis Path Traversal in Fireware Web UI. The current sources do not mark it as known exploited. The current feed maps WatchGuard/Fireware OS (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
A CVSS score is not reported in the current record. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps WatchGuard/Fireware OS (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| WatchGuard/Fireware OSgeneric | >=2025.1 <2026.2 || >=12.6.1 <12.12 | 2026.2, 12.12 |
Published upstream
Apr 1, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Aug 10, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Aug 10, 2026
A path traversal vulnerability in the Fireware OS Web UI on WatchGuard Firebox systems may allow a privileged authenticated remote attacker to execute arbitrary code in the context of an elevated system process.
Quoted source text, attributed separately from HOL analysis.