---
title: "CVE-2026-80976: Linux Kernel - Out-of-Bounds Read"
description: "Linux kernel contains a buffer out-of-bounds vulnerability caused by stale IPv6 control block values after IPv6 decapsulation in seg6, letting unprivileged users read beyond skb head, exploit requires local SID installation and packet injection."
url: https://panop.io/threat-heartbeat/CVE-2026-80976/
---

# CVE-2026-80976 Linux Kernel - Out-of-Bounds Read

Linux kernel contains a buffer out-of-bounds vulnerability caused by stale IPv6 control block values after IPv6 decapsulation in seg6, letting unprivileged users read beyond skb head, exploit requires local SID installation and packet injection.

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-2026-80976)

## Details

Type

Out-of-Bounds Read

Impact

Denial Of Service, Information Disclosure

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 IP6CB reset after IPv6 decapsulation.

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-2026-80976](https://nvd.nist.gov/vuln/detail/CVE-2026-80976)
- [https://git.kernel.org/stable/c/f967455fb2a5a2079b9eb5823e9ccf359174bf9f](https://git.kernel.org/stable/c/f967455fb2a5a2079b9eb5823e9ccf359174bf9f)
- [https://git.kernel.org/stable/c/96c74420ac92930a7e0f21770818544eee4a93d7](https://git.kernel.org/stable/c/96c74420ac92930a7e0f21770818544eee4a93d7)
- [https://git.kernel.org/stable/c/9ae92198c24d7dacd4070e2f34f6e1ed3a63061c](https://git.kernel.org/stable/c/9ae92198c24d7dacd4070e2f34f6e1ed3a63061c)
- [https://git.kernel.org/stable/c/a0e2b0a3718f0cf9fb0ee41710b4a6348a7315c8](https://git.kernel.org/stable/c/a0e2b0a3718f0cf9fb0ee41710b4a6348a7315c8)
- [https://git.kernel.org/stable/c/d1f0d353358987ca87f21d8956e2d2854951130d](https://git.kernel.org/stable/c/d1f0d353358987ca87f21d8956e2d2854951130d)
- [https://git.kernel.org/stable/c/2b154e96fcb3f01fd42765c64e0a56820fbc16eb](https://git.kernel.org/stable/c/2b154e96fcb3f01fd42765c64e0a56820fbc16eb)
- [https://git.kernel.org/stable/c/c73fb911e02b9a766c950bc9707f3e3a96ffd702](https://git.kernel.org/stable/c/c73fb911e02b9a766c950bc9707f3e3a96ffd702)
- [https://git.kernel.org/stable/c/cfa186a0857a0f831dfca67b16bbc40ecfdf3280](https://git.kernel.org/stable/c/cfa186a0857a0f831dfca67b16bbc40ecfdf3280)

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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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