Cisco ASA/FTD firewalls can be crashed remotely; attacks confirmed
Original title：CISA KEV added CVE-2026-76418: Cisco Secure Firewall ASA Software and Cisco Secure FTD Software – Cisco Secure Firewall ASA Software and Cisco Secure FTD Software Unchecked Return Value to NULL Pointer Dereference Vulnerability
What happened
A flaw in Cisco Secure Firewall ASA and FTD lets an unauthenticated remote attacker force the device to reload, causing denial of service. CISA lists it as exploited in the wild, so affected network operations may be disrupted.
Who is affected
- Organizations running Cisco ASA or FTD
- Agencies managing client firewalls
What to do
Check Cisco's advisory for affected and fixed versions and update your ASA/FTD devices promptly. Also review logs for unexpected reloads.
Affected products
| Product | Affected | Fixed in |
|---|---|---|
| Cisco Secure Firewall ASA Software | 要確認 | 要確認 |
| Cisco Secure Firewall Threat Defense (FTD) Software | 要確認 | 要確認 |
Why this flag
CISA KEV に掲載（悪用確認済み）かつ重大な影響
Red flag: session stopped — Exploitation confirmed with major impact. Assigned only when listed in CISA KEV or confirmed by a primary source.
Sources
- Primary source：CISA Known Exploited Vulnerabilities ↗
- CVE：CVE-2026-76418 ↗