---
title: "CVE-2026-89603: Linux Kernel - Race Condition"
description: "Linux kernel contains a race condition in seccomp filter handling with ptrace and TSYNC, allowing unprivileged processes to bypass seccomp filters and execute prohibited syscalls, exploit requires concurrent thread interaction."
url: https://panop.io/threat-heartbeat/CVE-2026-89603/
---

# CVE-2026-89603 Linux Kernel - Race Condition

Linux kernel contains a race condition in seccomp filter handling with ptrace and TSYNC, allowing unprivileged processes to bypass seccomp filters and execute prohibited syscalls, exploit requires concurrent thread interaction.

CVSS base score 8.4 /10

High

CISA KEV

Not listed

Public exploit

None known

EPSS

0.14% chance of exploitation in 30 days

[View the NVD record ↗](https://nvd.nist.gov/vuln/detail/CVE-2026-89603)

## Details

Type

Race Condition

Impact

Privilege Escalation

CVSS vector

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

Published

11 September 2026

Updated

15 October 2026

## Vendor fix

Update to the latest Linux kernel version with the seccomp bypass fix.

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-2026-89603](https://nvd.nist.gov/vuln/detail/CVE-2026-89603)
- [https://git.kernel.org/stable/c/23001ee5d8631e30192cde6f6d3ccb6805570499](https://git.kernel.org/stable/c/23001ee5d8631e30192cde6f6d3ccb6805570499)
- [https://git.kernel.org/stable/c/8709e7e1dd7d7de0651e61700edf24f5784f9243](https://git.kernel.org/stable/c/8709e7e1dd7d7de0651e61700edf24f5784f9243)
- [https://git.kernel.org/stable/c/eca5ed4200f0be3e91f8a237b1f37582030a93a8](https://git.kernel.org/stable/c/eca5ed4200f0be3e91f8a237b1f37582030a93a8)
- [https://git.kernel.org/stable/c/459f33f82864723a7fa366cf1091d9c6c893b6b2](https://git.kernel.org/stable/c/459f33f82864723a7fa366cf1091d9c6c893b6b2)
- [https://git.kernel.org/stable/c/4a3591287fb7f808e209b4974ed337f609a2006b](https://git.kernel.org/stable/c/4a3591287fb7f808e209b4974ed337f609a2006b)
- [https://git.kernel.org/stable/c/ab4647459098a43e9d6fdb860836f08c962f3774](https://git.kernel.org/stable/c/ab4647459098a43e9d6fdb860836f08c962f3774)
- [https://git.kernel.org/stable/c/09e8880ce5409bdb84da991b053d7087502c181e](https://git.kernel.org/stable/c/09e8880ce5409bdb84da991b053d7087502c181e)
- [https://git.kernel.org/stable/c/22bb836fc133331982c264227a899d4b26a09706](https://git.kernel.org/stable/c/22bb836fc133331982c264227a899d4b26a09706)

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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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