Cisco Snort 3 GRE decapsulation flaw (CVE-2026-20221) lets remote attacker crash detection engine
Cisco disclosed CVE-2026-20221, a vulnerability in the generic routing encapsulation (GRE) tunnel decapsulation feature of the Snort 3 Detection Engine that affects multiple Cisco products. An unauthenticated, remote attacker can send a crafted GRE payload through an affected device to trigger an unexpected restart of the engine. Dependin…