Denial of Service Vulnerability in Cisco Snort 3 SMTP MIME Decoder

CVE-2026-20011

What is CVE-2026-20011?

A vulnerability exists in the Cisco Snort 3 SMTP MIME Decoder, where insufficient error checking during the parsing of MIME fields in SMTP headers could be exploited by an unauthenticated remote attacker. By sending specially crafted SMTP packets through an established connection, the attacker can trigger a restart of the Snort 3 Detection Engine, leading to a denial of service (DoS) condition. This situation can disrupt normal operations, affecting network security monitoring and threat detection capabilities.

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