Cisco Snort 3/Threat Defense Software Memory Management denial of service

Summaryinfo

A vulnerability was found in Cisco Snort 3 and Threat Defense Software. It has been rated as critical. Affected is an unknown function of the component Memory Management. The manipulation leads to denial of service. This vulnerability is uniquely identified as CVE-2026-76489. The attack is possible to be carried out remotely. No exploit exists. Upgrading the affected component is advised.

Detailsinfo

A vulnerability was found in Cisco Snort 3 and Threat Defense Software (version unknown). It has been rated as critical. This issue affects an unknown function of the component Memory Management. The manipulation with an unknown input leads to a denial of service vulnerability. Using CWE to declare the problem leads to CWE-404. The product does not release or incorrectly releases a resource before it is made available for re-use. Impacted is availability. The summary by CVE is:

Multiple Cisco products are affected by a vulnerability in the memory management implementation of Snort 3 that could allow an unauthenticated, remote attacker to cause the Snort 3 Detection Engine to restart, resulting in an interruption of packet inspection. This vulnerability is due to incomplete error checking when Snort 3 processes files, which could cause unreleased memory. An attacker could exploit this vulnerability by sending a large number of files to be processed. A successful exploit could allow the attacker to cause the Snort 3 Detection Engine to restart unexpectedly, resulting in a DoS condition.

It is possible to read the advisory at sec.cloudapps.cisco.com. The identification of this vulnerability is CVE-2026-76489 since 08/19/2026. The exploitation is known to be easy. The attack may be initiated remotely. No form of authentication is needed for a successful exploitation. The technical details are unknown and an exploit is not publicly available. The pricing for an exploit might be around USD $0-$5k at the moment (estimation calculated on 10/21/2026). The attack technique deployed by this issue is T1499 according to MITRE ATT&CK.

Upgrading eliminates this vulnerability.

Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Productinfo

Vendor

• Cisco

Name

• Snort 3
• Threat Defense Software

License

• commercial

Website

• Vendor: https://www.cisco.com/

CPE 2.3info

• 🔒
• 🔒

CPE 2.2info

• 🔒
• 🔒

CVSSv4info

CVSSv3info

CVSSv2info

Exploitinginfo

Threat Intelligenceinfo

Countermeasuresinfo

Timelineinfo

Sourcesinfo

Entryinfo

Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Discussion