---
title: "CVE-2026-98258: Linux Kernel - Use-After-Free"
description: "Linux kernel contains a use-after-free vulnerability in POSIX CPU timers caused by improper handling of timer firing state during expiry list operations, letting attackers cause memory corruption, exploit requires triggering timer expiry and deletion race conditions."
url: https://panop.io/threat-heartbeat/CVE-2026-98258/
---

# CVE-2026-98258 Linux Kernel - Use-After-Free

Linux kernel contains a use-after-free vulnerability in POSIX CPU timers caused by improper handling of timer firing state during expiry list operations, letting attackers cause memory corruption, exploit requires triggering timer expiry and deletion race conditions.

CVSS base score 7.8 /10

High

CISA KEV

Not listed

Public exploit

None known

Authentication

Required

EPSS

0.14% chance of exploitation in 30 days

[View the NVD record ↗](https://nvd.nist.gov/vuln/detail/CVE-2026-98258)

## Details

Type

Use-After-Free

CVSS vector

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

Published

6 October 2026

Updated

15 October 2026

## References

- [https://nvd.nist.gov/vuln/detail/CVE-2026-98258](https://nvd.nist.gov/vuln/detail/CVE-2026-98258)
- [https://git.kernel.org/stable/c/c21eaa72f02fc6e85621cbe09d303d8fb8bd39cd](https://git.kernel.org/stable/c/c21eaa72f02fc6e85621cbe09d303d8fb8bd39cd)
- [https://git.kernel.org/stable/c/4336e3f47d9d516441066e9a65eaf076790d8d45](https://git.kernel.org/stable/c/4336e3f47d9d516441066e9a65eaf076790d8d45)
- [https://git.kernel.org/stable/c/9971dac1a77845ff467146915fcbb9170f6a8209](https://git.kernel.org/stable/c/9971dac1a77845ff467146915fcbb9170f6a8209)

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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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