CVE-2026-20221

Published: Ott 21, 2026 Last Modified: Ott 21, 2026
ExploitDB:
Other exploit source:
Google Dorks:
MEDIUM 5,8
Source: [email protected]
Attack Vector: network
Attack Complexity: low
Privileges Required: none
User Interaction: none
Scope: changed
Confidentiality: none
Integrity: none
Availability: low

Description

AI Translation Available

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.

476

NULL Pointer Dereference

Stable
Abstraction: Base Structure: Simple
Common Consequences
Security Scopes Affected:
Availability Integrity Confidentiality
Potential Impacts:
Dos: Crash, Exit, Or Restart Execute Unauthorized Code Or Commands Read Memory Modify Memory
Applicable Platforms
Languages: C, C++, Java, C#, Go
Likelihood of Exploit: Medium
View CWE Details
https://sec.cloudapps.cisco.com/security/center/content/Cis…
https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/c…