CVE-2026-98491

In the Linux kernel, the following vulnerability has been resolved: net: openvswitch: conntrack: avoid modifying shared unconfirmed ct entry In a case where skb with an unconfirmed ct entry gets cloned, we may end up committing both but with different sets of extensions. The series of events: 1. The first clone wants to commit and runs the helpers wiring up the extension pointer into the expectation list. 2. Then it looses the confirmation keeping the entry unconfirmed. 3. Second clone now wants to commit labels and adds the new extension for that breaking the pointer in the expectation list causing UAF on the destruction path later. While this is possible to trigger, there should be no practical network pipeline where committing both clones without modifications into the same zone is needed. So, let's just reset the entry in case for some reason we got an skb with a shared one during commit. This doesn't affect any known use cases, but avoids any potential problems with sharing and modification of the unconfirmed ct entry. The fixes tag points to the introduction of helpers, since that's the main UAF trigger for the sharing.

Package Linux Kernel
Published 2026-10-18
Last modified 2026-10-18
Patch available
Yes

Affected versions

Linux kernel versions 4.3 and later are affected. Fixed in 5.10.271, 5.15.222, 6.1.189, 6.6.158, 6.12.112, 6.18.55, 7.2.9, 7.3 and their respective stable series.

Affected from
≥ 4.3
Fixed in
✓ 5.10.271 5.10.x ✓ 5.15.222 5.15.x ✓ 6.1.189 6.1.x ✓ 6.6.158 6.6.x ✓ 6.12.112 6.12.x ✓ 6.18.55 6.18.x ✓ 7.2.9 7.2.x ✓ 7.3

Frequently asked questions

  • What is CVE-2026-98491?

    CVE-2026-98491 is a unscored severity Linux kernel vulnerability . It affects Linux kernel versions from 4.3 onward and has been patched in 5.10.271, 5.15.222, 6.1.189 and others. CVE-2026-98491 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

  • Is there a patch available for CVE-2026-98491?

    Yes. CVE-2026-98491 has been patched. Fixed versions include 5.10.271, 5.15.222, 6.1.189 and others. If you are running Linux kernel 4.3 or later up to the fix versions, apply the relevant patch for your kernel branch.

  • Is CVE-2026-98491 actively exploited?

    No. CVE-2026-98491 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.