---
title: "CVE-2026-89503: Linux Kernel - Race Condition"
description: "Linux kernel contains a race condition in ring_buffer_alloc_read_page() caused by concurrent subbuf_order changes, letting attackers cause memory allocation inconsistencies, exploit requires concurrent access to ring buffer."
url: https://panop.io/threat-heartbeat/CVE-2026-89503/
---

# CVE-2026-89503 Linux Kernel - Race Condition

Linux kernel contains a race condition in ring\_buffer\_alloc\_read\_page() caused by concurrent subbuf\_order changes, letting attackers cause memory allocation inconsistencies, exploit requires concurrent access to ring buffer.

CVSS base score 7.8 /10

High

CISA KEV

Not listed

Public exploit

None known

Authentication

Required

EPSS

0.16% chance of exploitation in 30 days

[View the NVD record ↗](https://nvd.nist.gov/vuln/detail/CVE-2026-89503)

## Details

Type

Race Condition

Impact

Denial Of Service

CVSS vector

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

Published

11 September 2026

Updated

15 October 2026

## References

- [https://nvd.nist.gov/vuln/detail/CVE-2026-89503](https://nvd.nist.gov/vuln/detail/CVE-2026-89503)
- [https://git.kernel.org/stable/c/2dc510957fe8fd098ab3c3147ebdf34d00cd2734](https://git.kernel.org/stable/c/2dc510957fe8fd098ab3c3147ebdf34d00cd2734)
- [https://git.kernel.org/stable/c/53106e9262a310ef2c9a9321168c03705940c678](https://git.kernel.org/stable/c/53106e9262a310ef2c9a9321168c03705940c678)
- [https://git.kernel.org/stable/c/e743527c5bfdceda1095bc0a9e596e2aebb6a9c3](https://git.kernel.org/stable/c/e743527c5bfdceda1095bc0a9e596e2aebb6a9c3)
- [https://git.kernel.org/stable/c/2313ff69bd237aad264a5913907f374f958335a2](https://git.kernel.org/stable/c/2313ff69bd237aad264a5913907f374f958335a2)

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- Whether an attacker can actually reach and exploit it
- The misconfigurations that never get a CVE number
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