---
description: New managed rule to help mitigate CVE-2026-98432.
title: New managed rule to help mitigate CVE-2026-98432.
image: https://developers.cloudflare.com/changelog/post/2026-11-04-cve-2026-98432-managed-rule/og.png?v=44413efb3b86ea8f
---

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November 4, 2026

## New managed rule to help mitigate CVE-2026-98432.

[Cloudflare Network Firewall](https://developers.cloudflare.com/cloudflare-network-firewall/)

Copy as Markdown| [View as Markdown](https://developers.cloudflare.com/changelog/post/2026-11-04-cve-2026-98432-managed-rule/index.md)| [Agent setup](https://developers.cloudflare.com/agent-setup/)

Cloudflare Network Firewall has a new managed rule to help mitigate the Linux IPv4 TCP use-after-free vulnerability ([CVE-2026-98432 ↗︎](https://www.cve.org/CVERecord?id=CVE-2026-98432)):

- **Rule name:** Block CVE-2026-98432 traffic
- **Rule ID:** `6a4df2bf984946a88c74b07349557e83`

The rule is **disabled by default**. To use it:

1. Go to **Networking** > **Firewall Policies** > **Managed Rulesets**.
2. Enable the rule with action **Log** first.
3. Review traffic that matches the rule.
4. If the matching traffic is not expected for your environment, change the action to **Block**.

For more information on enabling managed rulesets, refer to [Enable managed rulesets](https://developers.cloudflare.com/cloudflare-network-firewall/how-to/enable-managed-rulesets/).

For more details about the vulnerability, including an agent assessment prompt and evidence sources, refer to the [Cloudflare Radar Zero Wire briefing ↗︎](https://radar.cloudflare.com/security/zero-wire/linux-ipv4-tcp-use-after-free).

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