---
title: "CVE-2026-89542: Linux Kernel - Memory Corruption & Denial of Service"
description: "Linux kernel contains a buffer over-read and integer underflow vulnerability in SUNRPC gss_krb5_unwrap_v2 caused by insufficient validation of token length and buffer boundaries, letting attackers cause memory corruption or denial of service, exploit requires crafted short tokens."
url: https://panop.io/threat-heartbeat/CVE-2026-89542/
---

# CVE-2026-89542 Linux Kernel - Memory Corruption & Denial of Service

Linux kernel contains a buffer over-read and integer underflow vulnerability in SUNRPC gss\_krb5\_unwrap\_v2 caused by insufficient validation of token length and buffer boundaries, letting attackers cause memory corruption or denial of service, exploit requires crafted short tokens.

CVSS base score 9.8 /10

Critical

CISA KEV

Not listed

Public exploit

None known

Authentication

Not required

EPSS

0.51% chance of exploitation in 30 days

[View the NVD record ↗](https://nvd.nist.gov/vuln/detail/CVE-2026-89542)

## Details

Type

Memory Corruption

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

11 September 2026

Updated

15 October 2026

## Vendor fix

Update to the latest Linux kernel version containing the fix for SUNRPC gss\_krb5\_unwrap\_v2.

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-2026-89542](https://nvd.nist.gov/vuln/detail/CVE-2026-89542)
- [https://git.kernel.org/stable/c/dddcb0f4b7e27fac16a78ea9a1c8ec2e8a241087](https://git.kernel.org/stable/c/dddcb0f4b7e27fac16a78ea9a1c8ec2e8a241087)
- [https://git.kernel.org/stable/c/075d7cfc4df8c54cb202ba8b28420370c03ba9b6](https://git.kernel.org/stable/c/075d7cfc4df8c54cb202ba8b28420370c03ba9b6)
- [https://git.kernel.org/stable/c/299d281c7225ded15b28cb861a98d818d82787fc](https://git.kernel.org/stable/c/299d281c7225ded15b28cb861a98d818d82787fc)
- [https://git.kernel.org/stable/c/84ddbc8d084c0251d534f14f5d1a7da05be56404](https://git.kernel.org/stable/c/84ddbc8d084c0251d534f14f5d1a7da05be56404)
- [https://git.kernel.org/stable/c/f2591660e0eb263c9415bf0d0bb1b111e62df7a4](https://git.kernel.org/stable/c/f2591660e0eb263c9415bf0d0bb1b111e62df7a4)
- [https://git.kernel.org/stable/c/6959297aaa9572783d620a226d73c3fb94494888](https://git.kernel.org/stable/c/6959297aaa9572783d620a226d73c3fb94494888)
- [https://git.kernel.org/stable/c/806584a4b67a7233870c33e5b8f872e76dd02988](https://git.kernel.org/stable/c/806584a4b67a7233870c33e5b8f872e76dd02988)
- [https://git.kernel.org/stable/c/a7894e10572d53eb10109b8d07459cc8d3435811](https://git.kernel.org/stable/c/a7894e10572d53eb10109b8d07459cc8d3435811)

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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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