# CVE-2026-98442: Linux kernel use-after-free in conntrack helper

Source: https://junglewise.ai/threats/cve-2026-98442-in-the-linux-kernel-the-following-vulnerability-has-been-resolved  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-10-18. Updated: 2026-10-18  
License: CC BY 4.0 with a link back

CVE-2026-98442 · Severity: info · Published 2026-10-18

The Linux kernel's network connection tracking scheduler contains a use-after-free vulnerability in the conntrack helper code. When processing network connections, a pointer to an extensions buffer is stored in a list, but if the buffer is later reallocated to add more extensions, the stored pointer becomes invalid. This can cause a kernel crash or memory corruption when the stale pointer is accessed.

Technologies: [Linux](https://junglewise.ai/threats/technologies/linux-linux). Vendors: [Linux](https://junglewise.ai/threats/vendors/linux).

## Quick answers

**Is CVE-2026-98442 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-98442 being exploited in the wild.

**How severe is CVE-2026-98442?** Informational severity, published 18 October 2026.

**Which products and versions are affected?** Linux multiple versions prior to fix.

**Is there a fix for CVE-2026-98442?** A patch was published on 2026-10-03. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-98442 attacked?** It is attacked with local access, in an operating system.

**Am I affected by CVE-2026-98442?** Check whether you run Linux at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

A use-after-free exists in net/sched/act_ct.c where a raw pointer to the extensions area is wired into the expectations list before all extensions are added. If the connection is not yet confirmed, subsequent calls to *_ext_add() can reallocate the extension space, leaving an invalid pointer in the expectations list. The fix reorders operations to call nf_ct_helper() after all extensions have been added, eliminating the reallocation window.

## Affected products

- Linux Linux multiple versions prior to fix

## Timeline

- 2026-09-29: disclosed
- 2026-10-03: patched
- 2026-10-18: advisory

## References

- [https://git.kernel.org/stable/c/1679bbf5fbeac52a310b1a58b2b301bbf388bdbf](https://git.kernel.org/stable/c/1679bbf5fbeac52a310b1a58b2b301bbf388bdbf)
- [https://git.kernel.org/stable/c/812c16a255e7773a544e88b39ae6daed25544d30](https://git.kernel.org/stable/c/812c16a255e7773a544e88b39ae6daed25544d30)

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