---
title: "CVE-2026-81003: Linux Kernel - Broken Access Control"
description: "Linux kernel contains an AF_IUCV socket binding vulnerability caused by lack of ingress device verification in afiucv_hs_rcv(), letting attackers inject data, exhaust accept queues, or spoof peers across network namespaces, exploit requires sending crafted frames on the same HiperSockets segment."
url: https://panop.io/threat-heartbeat/CVE-2026-81003/
---

# CVE-2026-81003 Linux Kernel - Broken Access Control

Linux kernel contains an AF\_IUCV socket binding vulnerability caused by lack of ingress device verification in afiucv\_hs\_rcv(), letting attackers inject data, exhaust accept queues, or spoof peers across network namespaces, exploit requires sending crafted frames on the same HiperSockets segment.

CVSS base score 8.1 /10

High

CISA KEV

Not listed

Public exploit

None known

Authentication

Not required

EPSS

0.31% chance of exploitation in 30 days

[View the NVD record ↗](https://nvd.nist.gov/vuln/detail/CVE-2026-81003)

## Details

Type

Broken Access Control

Impact

Denial Of Service, Data Tampering, Information Disclosure

CVSS vector

CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/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 ingress device verification in afiucv\_hs\_rcv()

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-2026-81003](https://nvd.nist.gov/vuln/detail/CVE-2026-81003)
- [https://git.kernel.org/stable/c/80230a18c164a4b5bbc048fe2768b219ac17bc5a](https://git.kernel.org/stable/c/80230a18c164a4b5bbc048fe2768b219ac17bc5a)
- [https://git.kernel.org/stable/c/8e3763f1ccac3fc395f9af2b87114c023ced8a3f](https://git.kernel.org/stable/c/8e3763f1ccac3fc395f9af2b87114c023ced8a3f)
- [https://git.kernel.org/stable/c/a7f0130a091724e69827ab58e74777a88747e892](https://git.kernel.org/stable/c/a7f0130a091724e69827ab58e74777a88747e892)
- [https://git.kernel.org/stable/c/dfac2936b83be00035ae176f8252e1c1e1de9207](https://git.kernel.org/stable/c/dfac2936b83be00035ae176f8252e1c1e1de9207)
- [https://git.kernel.org/stable/c/0a5af67e7184c6a0e155c317840bd64b37177af4](https://git.kernel.org/stable/c/0a5af67e7184c6a0e155c317840bd64b37177af4)
- [https://git.kernel.org/stable/c/639828ad4d374056167391dbaffd13dd5e5e5ddb](https://git.kernel.org/stable/c/639828ad4d374056167391dbaffd13dd5e5e5ddb)
- [https://git.kernel.org/stable/c/712330f8a4293cfd97b0d62b7c7dc01862a16b98](https://git.kernel.org/stable/c/712330f8a4293cfd97b0d62b7c7dc01862a16b98)
- [https://git.kernel.org/stable/c/92e5c281f1caa287bb58292f2687c9e3ff3aa23e](https://git.kernel.org/stable/c/92e5c281f1caa287bb58292f2687c9e3ff3aa23e)

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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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