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Medium 5.8

Multiple Cisco products are affected by a vulnerability in the generic routing encapsulation (GRE...

CVE-2026-20221 First seen on SecPulse

Affected packages

EcosystemPackageAffectedFixed
Cisco Cisco Cyber Vision — —
Cisco Cisco Open Source Snort3 — —
Cisco Cisco Secure Firewall Threat Defense (FTD) Software — —
Cisco Cisco Umbrella Insights Virtual Appliance — —
Cisco Cisco UTD SNORT IPS Engine Software — —
Original description The description as published by the source.

Multiple Cisco products are affected by a vulnerability in the generic routing encapsulation (GRE) tunnel decapsulation feature of the Snort 3 Detection Engine that could allow an unauthenticated, remote attacker to cause an unexpected restart of the Snort 3 Detection Engine.

This vulnerability is due to improper handling of nested GRE traffic. An attacker could exploit this vulnerability by sending a crafted GRE payload through an affected device. A successful exploit could allow the attacker to trigger an unexpected reload of the Snort 3 Detection Engine, resulting in either a bypass or denial of service (DoS) condition, depending on device configuration. For more information, see the section of this advisory. The Snort 3 Detection Engine will restart automatically. No manual intervention is required.

Source: CVE.org (CVE Program・cvelistV5) NVD GitHub Advisory

References

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