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.
Analysis
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Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).
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| Cisco | Cisco Secure Firewall Threat Defense (FTD) Software | unknown |
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Thu, 17 Sep 2026 14:30:00 +0000
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ssvc
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Wed, 16 Sep 2026 20:30:00 +0000
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| Description | 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. | |
| Title | Cisco Secure Firewall Threat Defense Software TLS 1.3 Denial of Service Vulnerability | |
| Weaknesses | CWE-415 | |
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| Metrics |
cvssV3_1
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Subscriptions
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MITRE
Status: PUBLISHED
Assigner: cisco
Published:
Updated: 2026-09-17T13:40:57.832Z
Reserved: 2025-10-08T11:59:15.381Z
Link: CVE-2026-20135
Vulnrichment
Updated: 2026-09-17T13:36:15.500Z
NVD
Status : Received
Published: 2026-09-16T21:17:07.587
Modified: 2026-09-17T14:17:12.670
Link: CVE-2026-20135
Redhat
No data.
OpenCVE Enrichment
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CWE-415
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