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Severe, 6 weeks1496Projects326

1496 severe, 6 weeks · 326 projects

CiscoCVE-2026-20135

Cisco Secure Firewall Threat Defense (FTD) Software: denial of service

Cisco

CVE-2026-20135 · Published Sep 16, 2026 · updated Sep 18, 2026

High8.6
No fix yet
Cisco advisory

A vulnerability in the TLS 1.3 implementation in Cisco Secure Firewall Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause an affected device to reload unexpectedly, resulting in a denial of service (DoS) condition.

This vulnerability is due to improper buffer management during the TLS 1.3 connection. An attacker could exploit this vulnerability by sending a crafted TLS 1.3 packet to an affected system through a TLS 1.3-enabled listening socket. A successful exploit could allow the attacker to cause the LINA process to crash, which would cause the device to reload. The reload can happen before or after authentication of the connection.Note: TLS 1.3 connections include both data traffic and user-management traffic.

Affected versions

PackageAffectedFixed in
Cisco Secure Firewall Threat Defense (FTD) Software
Product
<= 7.0.0No fix yet
<= 7.0.0.1No fix yet
<= 7.0.1No fix yet
<= 7.0.1.1No fix yet
Details and references

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