CVE-2026-93866
Fireware OS Pre-Authentication Integer Overflow in Access Portal Allows Out-of-Bounds Write
No known exploitation. EPSS puts it in the 43rd percentile. Fixed versions are out.
No public exploit knownFix1 product2 fixed builds listed below
No ready-made check. Neither Nuclei nor OpenVAS has one for this CVE yet.
What to do
Find your product and version, then upgrade to the build on the right.
- WatchGuard Fireware OSAffected: ≥ 2025.1, < 2026.4Upgrade to: 2026.4Affected: ≥ 12.0, < 12.12.4Upgrade to: 12.12.4Stated by: CVE record
Versions as the sources state them. Full version matrix after sign-in
What it is
From the CVE record
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.
In plain language
No plain-language summary for this CVE yet.
Exploitation
Where each signal puts this CVE on the scale from published to confirmed exploited.
- CISA KEV
Not in the catalog. CISA has not confirmed exploitation.
- Public exploits
No public exploit or proof of concept found in the sources we track.
- EPSS
0.5% chance of exploitation activity in the next 30 days, which ranks it in the 43rd percentile of scored CVEs.
Exploit Prediction Scoring System, FIRST.org. A probability, not a confirmation.
Lifecycle
8 events over 1 day, from the signal feeds we watch.
- Patch availablerecord updated
- Patch availablepatch available, published, weakness classified, att&ck mapped, record updated
Affected products
Technical detail
Weaknesses
ATT&CK techniques
Mapped from the weaknesses above (CWE to ATT&CK), not observed in attacks.
- Initial AccessT1190Exploit Public-Facing Applicationhigh confidence
- Privilege EscalationT1068Exploitation for Privilege Escalationhigh confidence
Sources
References in the record
In the news
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