---
title: "CVE-2026-99078: Linux kernel - Use After Free"
description: "Linux kernel net/mlx5e contains a use-after-free vulnerability caused by stale XSK buffer release on MPWQE refill retry in AF_XDP striding RQ, letting attackers cause memory corruption, exploit requires AF_XDP usage with specific buffer allocation failures."
url: https://panop.io/threat-heartbeat/CVE-2026-99078/
---

# CVE-2026-99078 Linux kernel - Use After Free

Linux kernel net/mlx5e contains a use-after-free vulnerability caused by stale XSK buffer release on MPWQE refill retry in AF\_XDP striding RQ, letting attackers cause memory corruption, exploit requires AF\_XDP usage with specific buffer allocation failures.

CVSS base score 9.8 /10

Critical

CISA KEV

Not listed

Public exploit

None known

EPSS

0.22% chance of exploitation in 30 days

[View the NVD record ↗](https://nvd.nist.gov/vuln/detail/CVE-2026-99078)

## Details

Type

Use After Free

Impact

Denial Of Service

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Published

23 October 2026

Updated

25 October 2026

## Vendor fix

Update to the latest Linux kernel version containing the fix for net/mlx5e stale XSK buffer release.

Patching closes this CVE. It does not tell you which of your systems run the affected version, or what else is exposed alongside them.

## References

- [https://nvd.nist.gov/vuln/detail/CVE-2026-99078](https://nvd.nist.gov/vuln/detail/CVE-2026-99078)
- [https://git.kernel.org/stable/c/63811edf512584c946e5e96b100e9e280703bbb5](https://git.kernel.org/stable/c/63811edf512584c946e5e96b100e9e280703bbb5)
- [https://git.kernel.org/stable/c/867119b4b588037724b85839d534465f0334d9bd](https://git.kernel.org/stable/c/867119b4b588037724b85839d534465f0334d9bd)
- [https://git.kernel.org/stable/c/d215d09606b0fcd18ad1eb532995782a21cea49d](https://git.kernel.org/stable/c/d215d09606b0fcd18ad1eb532995782a21cea49d)
- [https://git.kernel.org/stable/c/f3a52e2ec2788a7f6b64137985c087188a54ad4f](https://git.kernel.org/stable/c/f3a52e2ec2788a7f6b64137985c087188a54ad4f)
- [https://git.kernel.org/stable/c/3d73a1164a8c6b4461907a65cb6c022ea4fd39af](https://git.kernel.org/stable/c/3d73a1164a8c6b4461907a65cb6c022ea4fd39af)

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## What this record can't tell you

- Whether you run the affected software, and where
- Whether an attacker can actually reach and exploit it
- The misconfigurations that never get a CVE number
- What it would cost the business, ranked into what to fix first

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