CVE-2026-20221
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.
- CVSS 3.1
- 5.8
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:L - EPSS
- 0.6% chance of exploitation in the next 30 days; higher than 47% of CVEs (scores of 2026-10-25)
- CWE
- CWE-476
- Published
- Modified
- Record from
- the NVD, synced