Vulnerability · Published Oct 21, 2026 · Assigned by cisco

CVE-2026-76445Multiple Cisco Products Snort 3 Denial of Service Vulnerability

Medium 5.3

In plain English

A medium-severity infinite loop in Cisco Open Source Snort3 from Cisco. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.5% (higher than 45% of all known vulnerabilities).

Severity (CVSS 3.1)5.3Medium
Exploit odds (30 days)0.5%top 55.1% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known

Official description

Multiple Cisco products are affected by a vulnerability in the Snort 3 Detection Engine that could allow an unauthenticated, remote attacker to cause the detection engine to unexpectedly restart, resulting in a denial of service (DoS) condition. The vulnerability is due to a flaw in logic handling when General Packet Radio Service (GPRS) Tunneling Protocol (GTP) extension headers are processed within the codec. An attacker could exploit this vulnerability by sending a crafted, fragmented UDP datagram that contains these headers to the Snort 3 Detection Engine of an affected device. A successful exploit could allow the attacker to cause the detection engine to enter an infinite loop, resulting in a DoS condition.

Affected products (as reported)

VendorProductVersions
Cisco Cisco Open Source Snort3 3.12.2.03.1.2.03.1.3.03.1.4.03.1.5.03.1.6.03.1.7.03.1.8.0
Cisco Cisco Secure Firewall Threat Defense (FTD) Software 7.0.07.0.0.17.0.17.0.1.17.0.27.2.07.0.2.17.0.3
Cisco Cisco UTD SNORT IPS Engine Software 17.12.1a17.12.217.12.317.12.417.12.3a17.15.1a17.12.4a17.15.2c

Weakness: CWE-835 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

References