---
title: "CVE-2026-89783: Linux Kernel - Out of Bounds Write"
description: "Linux kernel contains an out-of-bounds write vulnerability in xfrm6_input_addr() due to an off-by-one error in secpath depth check, letting attackers cause memory corruption, exploit requires crafted IPv6 packets with specific headers."
url: https://panop.io/threat-heartbeat/CVE-2026-89783/
---

# CVE-2026-89783 Linux Kernel - Out of Bounds Write

Linux kernel contains an out-of-bounds write vulnerability in xfrm6\_input\_addr() due to an off-by-one error in secpath depth check, letting attackers cause memory corruption, exploit requires crafted IPv6 packets with specific headers.

CVSS base score 9.8 /10

Critical

CISA KEV

Not listed

Public exploit

None known

Authentication

Not required

EPSS

0.71% chance of exploitation in 30 days

[View the NVD record ↗](https://nvd.nist.gov/vuln/detail/CVE-2026-89783)

## Details

Type

Out of Bounds Write

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

16 September 2026

Updated

15 October 2026

## Vendor fix

Update to the latest Linux kernel version containing the fix for xfrm6\_input\_addr() secpath depth check.

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-2026-89783](https://nvd.nist.gov/vuln/detail/CVE-2026-89783)
- [https://git.kernel.org/stable/c/48996649222e95008cdb98cd58579e3fc8e5ee06](https://git.kernel.org/stable/c/48996649222e95008cdb98cd58579e3fc8e5ee06)
- [https://git.kernel.org/stable/c/5d9e3bf34fec9a5d237e4b7cef4a707bc2e091bc](https://git.kernel.org/stable/c/5d9e3bf34fec9a5d237e4b7cef4a707bc2e091bc)
- [https://git.kernel.org/stable/c/5f35a29a5eed3d80befd32050843ac88dea3d61a](https://git.kernel.org/stable/c/5f35a29a5eed3d80befd32050843ac88dea3d61a)
- [https://git.kernel.org/stable/c/68e8737fe8e72f085c608cff322b3d2de8340af1](https://git.kernel.org/stable/c/68e8737fe8e72f085c608cff322b3d2de8340af1)
- [https://git.kernel.org/stable/c/8fe2c53fb81f5ad5be43af2ad09583f7c78b4b77](https://git.kernel.org/stable/c/8fe2c53fb81f5ad5be43af2ad09583f7c78b4b77)
- [https://git.kernel.org/stable/c/91fc387f63c00ddfb5221127a17bac97549a8343](https://git.kernel.org/stable/c/91fc387f63c00ddfb5221127a17bac97549a8343)
- [https://git.kernel.org/stable/c/bdcda866c89f9a8b1acdabf02d26cde9fbe501d8](https://git.kernel.org/stable/c/bdcda866c89f9a8b1acdabf02d26cde9fbe501d8)
- [https://git.kernel.org/stable/c/0f679e0523ddfff3fb554336ceb874b0e51e9cd3](https://git.kernel.org/stable/c/0f679e0523ddfff3fb554336ceb874b0e51e9cd3)

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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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