---
id: "CVE-2026-20236"
kind: "vulnerability"
aliases: ["CVE-2026-20236"]
title: "Snort 3: hardening fixes for internal flaws in incorrect calculation"
severity: "high"
cvss: 7.5
epss: 0.00346
exploited: false
status: "open"
category: "infrastructure"
products: []
ecosystems: []
tags: ["infrastructure", "network-security", "self-hosted", "snort"]
not_affected_if: []
published_at: "2026-10-21T17:18:28+00:00"
first_seen_at: "2026-10-23T21:57:29+00:00"
updated_at: "2026-10-25T03:16:33+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-20236", "first_seen_at": "2026-10-23T21:57:29+00:00"}, {"source": "epss", "url": "https://api.first.org/data/v1/epss?cve=CVE-2026-20236", "first_seen_at": "2026-10-24T13:15:54+00:00"}]
---

# Snort 3: hardening fixes for internal flaws in incorrect calculation

Cisco's Snort 3 network intrusion detection software has several internally found flaws in incorrect calculation logic (CWE-682), fixed in hardening releases. The sources do not say what an attacker can do with them.

_Summary, check and fix written by a model from the sources; labelled as such._

## How to check

- unknown

## Fix

- Move Snort 3 to a hardening release that includes the fix, per Cisco's advisory (version not stated in the sources)

## Timeline

- 2026-10-23T21:57:29+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-20236
- 2026-10-24T13:15:54+00:00 epss https://api.first.org/data/v1/epss?cve=CVE-2026-20236

## From the sources

As part of Cisco's ongoing commitment to proactive security and product quality, the Cisco owned Open Source Snort 3 Software engineering team has conducted a comprehensive internal security review. This review resulted in software hardening releases that address multiple internally discovered vulnerabilities.

The vulnerabilities tracked by CVE-2026-20236 are related to issues concerning incorrect calculation that are grouped under the Common Weakness Enumeration (CWE) Base CWE-682.

---

_Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai_