CVE-2026-98490

In the Linux kernel, the following vulnerability has been resolved: net: openvswitch: conntrack: fix helper UAF due to extensions realloc While calling the helpers, a raw pointer to the extensions area is wired into expectations list: -> nf_ct_helper() -> helper->help() -> nf_ct_expect_related_report() -> nf_ct_expect_insert() -> hlist_add_head_rcu(&exp->lnode, &master_help->expectations) In case the connection is not confirmed yet, more extensions can be added afterwards with *_ext_add() calls reallocating the extension space and leaving the now invalid pointer in the expectations list that is later accessed while removing the expectation. Make sure that helpers are called at the end after all the other extensions are already added. Note that the helper rejection now leaves the mark and labels set, but that's not different from how the NAT was handled before or how the mark and the labels were handled on confirmation failure. And there are no atomicity guarantees provided by the API anyway.

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 6.12.112, 6.18.55, 7.2.9, 7.3 and their respective stable series.

Affected from
≥ 4.3
Fixed in
✓ 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-2026-98490?

    CVE-2026-98490 is a unscored severity Linux kernel vulnerability . It affects Linux kernel versions from 4.3 onward and has been patched in 6.12.112, 6.18.55, 7.2.9 and others. CVE-2026-98490 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

  • Is there a patch available for CVE-2026-98490?

    Yes. CVE-2026-98490 has been patched. Fixed versions include 6.12.112, 6.18.55, 7.2.9 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-2026-98490 actively exploited?

    No. CVE-2026-98490 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.