CVE-2025-20127

score

<0.1

cvss

7.7

epss

0.7%

published

2025-08-14

kev added

—

first seen

2026-10-21

Cisco Secure Firewall ASA and FTD Software for Firepower 3100 and 4200 Series devices contain a denial of service vulnerability caused by resource exhaustion in TLS 1.3 implementation with TLS_CHACHA20_POLY1305_SHA256 cipher, letting authenticated remote attackers cause device to stop accepting new SSL/TLS or VPN requests, exploit requires sending many TLS 1.3 connections with the specific cipher.