Vulnerability details
CVE-2026-93866
WatchGuard Fireware OS
Fireware OS Pre-Authentication Integer Overflow in Access Portal Allows Out-of-Bounds Write
CVSS 4.0
9.2Critical
Official description
An integer overflow vulnerability in the WebSocket connection handling used by WatchGuard Fireware OS's Access Portal allows a remote, unauthenticated attacker to write beyond the bounds of a heap buffer by sending a specially crafted request while the Access Portal feature is enabled.
CVSS scores
| Score | Version | Source | Vector |
|---|---|---|---|
| 9.2Critical | 4.0 | CVEProject cvelistV5 (CNA) (WatchGuard) | CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N |
Affected products
| Vendor | Product | Versions | Source |
|---|---|---|---|
| WatchGuard | Fireware OS | 12.0 ≤ v < 12.12.4 | CVEProject cvelistV5 (CNA) |
| WatchGuard | Fireware OS | 12.0 ≤ v < 12.5.22 | CVEProject cvelistV5 (CNA) |
| WatchGuard | Fireware OS | 2025.1 ≤ v < 2026.4 | CVEProject cvelistV5 (CNA) |
References and advisories
1- https://psirt.watchguard.com/CVE-2026-93866 vendor-advisory
Kolun on Telegram @kolunsec
Exploited CVEs, key news and a daily digest
Alerts for this product's next CVEsFollow the product to get new vulnerabilities on Telegram.
Details
- Published
- 2026-10-27
- Last updated
- 2026-11-04
- State
- Published
- Assigner (CNA)
- WatchGuard
- Kolun priority
- 25 · Low
Exploit prediction (EPSS)
0.5%
Probability of exploitation in 30 days
43.7%
Percentile (among all CVEs)
SSVC assessment (CISA)
- Automatable
- No
- Exploitation
- None
- Technical impact
- Total
Weaknesses (CWE)
- CWE-190
- CWE-288
- CWE-787