Description
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.
Published: 2026-10-21
Score: 5.8 Medium
EPSS: < 1% Very Low
KEV: No
Impact: Denial of Service via memory exhaustion
Action: Patch
AI Analysis

Impact

A flaw in Snort 3’s memory management can cause unreleased memory when processing file uploads, leading to a restart of the Detection Engine. The result is a temporary loss of packet inspection realest capability and a denial of service for network traffic routed through the affected device. This weakness is a classic memory leak scenario identified as CWE-401.

Affected Systems

The vulnerability affects Cisco’s Open Source Snort3 and the Cisco Secure Firewall Threat Defense (FTD) Software. No specific product versions are listed, so all deployments of these products are potentially impacted.

Risk and Exploitability

The CVSS score of 5.8 indicates moderate severity; the EPSS score is not available and the issue is not listed as a known exploited vulnerability by CISA. The attack can be carried out by an unauthenticated remote actor who sends a large volume of files to the Snort 3 engine, triggering the memory exhaustion. Once triggered, the engine restarts, providing a short‑term DoS that can be observed from the network traffic flow.

Generated by OpenCVE AI on October 22, 2026 at 04:58 UTC.

Remediation

No solution or workaround provided in the CVE record.

OpenCVE Recommended Actions

  • Apply the latest Cisco patch or upgrade to a firmware version that addresses the memory leak in Snort 3.
  • Configure the firewall or SNORT to limit or filter large file uploads that the detection engine processes.
  • Monitor system logs for repeated engine restarts and configure alerting to detect potential abuse patterns.

Generated by OpenCVE AI on October 22, 2026 at 04:58 UTC.

Tracking

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Advisories

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History

Thu, 22 Oct 2026 14:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Thu, 22 Oct 2026 12:30:00 +0000

Type Values Removed Values Added
First Time appeared Cisco
Cisco cisco Open Source Snort3
Cisco cisco Secure Firewall Threat Defense (ftd) Software
Cisco secure Firewall Threat Defense
Vendors & Products Cisco
Cisco cisco Open Source Snort3
Cisco cisco Secure Firewall Threat Defense (ftd) Software
Cisco secure Firewall Threat Defense

Wed, 21 Oct 2026 17:15:00 +0000

Type Values Removed Values Added
Description 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.
Title Multiple Cisco Products Snort 3 Generic File Processing Memory Exhaustion Denial of Service Vulnerability
Weaknesses CWE-401
References
Metrics cvssV3_1

{'score': 5.8, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:L'}

Subscriptions

Cisco Cisco Open Source Snort3 Cisco Secure Firewall Threat Defense (ftd) Software Secure Firewall Threat Defense
cve-icon MITRE

Status: PUBLISHED

Assigner: cisco

Published:

Updated: 2026-10-22T19:11:31.788Z

Reserved: 2026-08-19T12:02:03.640Z

Link: CVE-2026-76489

cve-icon Vulnrichment

Updated: 2026-10-22T13:35:13.097Z

cve-icon NVD

Status : Awaiting Analysis

Published: 2026-10-21T17:19:08.163

Modified: 2026-10-22T14:17:47.043

Link: CVE-2026-76489

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-10-22T12:00:07Z

Weaknesses
  • CWE-401

    Missing Release of Memory after Effective Lifetime