Cisco Secure Firewall ASA Software and Cisco Secure FTD Software
CVE-2026-76418
Cisco Secure Firewall ASA Software and Cisco Secure FTD Software contains an unchecked return value to NULL pointer dereference vulnerability that could allow an unauthenticated, remote attacker to cause the device to reload unexpectedly, resulting in a denial of service (DoS) condition.
What this means for your business
- It affects Cisco Secure Firewall ASA Software and Cisco Secure FTD Software. It matters if your company, or a supplier that handles your data, runs it.
- Attackers are already using it. CISA added it to its list of flaws used in real attacks on 29 October 2026.
- FIRST's prediction model gives it a 0.8% chance of attack attempts being seen in the next 30 days, ranking above 57% of all known flaws.
What to do
- 1Check whether your company or your suppliers run Cisco Secure Firewall ASA Software and Cisco Secure FTD Software.
- 2If you do, follow CISA's required action below. No patch reference has been published yet.
- 3Treat it as urgent. US federal agencies must fix it by 1 November 2026. That deadline does not apply to private companies, but it shows how seriously CISA takes it.
- 4Because attackers have used it, check the affected systems for signs of a break-in, not only for the update.
Fastnexa security experts
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Required action
Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines.
CISA’s wording, unedited. The notes it mentions are in CISA’s catalogue entry.
Scoring
- CVSS
- Not yet scored
Dates
- Published
- 2026-10-29
- Added to KEV
- 2026-10-29
- Remediation due
- 2026-11-01
- Sources
- CISA KEV
Coverage
- Cisco security advisory (AV26-1102) - Update 1Canadian Centre for Cyber Security · 2026-10-29