---
title: "CVE-2026-90399: Linux Kernel - Buffer Overflow"
description: "Linux kernel contains a buffer overflow caused by stride mismatch in ath12k_wmi_mac_phy_caps_parse() during mac_phy_caps buffer allocation and memcpy, letting attackers cause memory corruption, exploit requires crafted firmware TLVs."
url: https://panop.io/threat-heartbeat/CVE-2026-90399/
---

# CVE-2026-90399 Linux Kernel - Buffer Overflow

Linux kernel contains a buffer overflow caused by stride mismatch in ath12k\_wmi\_mac\_phy\_caps\_parse() during mac\_phy\_caps buffer allocation and memcpy, letting attackers cause memory corruption, exploit requires crafted firmware TLVs.

CVSS base score 8.4 /10

High

CISA KEV

Not listed

Public exploit

None known

Authentication

Not required

EPSS

0.18% chance of exploitation in 30 days

[View the NVD record ↗](https://nvd.nist.gov/vuln/detail/CVE-2026-90399)

## Details

Type

Buffer Overflow

Impact

Denial Of Service, Remote Code Execution

CVSS vector

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

Published

17 September 2026

Updated

15 October 2026

## Vendor fix

Update to the latest Linux kernel version containing the fix for ath12k stride mismatch.

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-2026-90399](https://nvd.nist.gov/vuln/detail/CVE-2026-90399)
- [https://git.kernel.org/stable/c/26f8f87f0a556e7984366c64cebc16d49e15d22f](https://git.kernel.org/stable/c/26f8f87f0a556e7984366c64cebc16d49e15d22f)
- [https://git.kernel.org/stable/c/4c6eb712a91fa079be6f9f1419c96e0ad2227081](https://git.kernel.org/stable/c/4c6eb712a91fa079be6f9f1419c96e0ad2227081)
- [https://git.kernel.org/stable/c/b9a5d12cbdeb860306f8d47c92caee0ea6ee0e0a](https://git.kernel.org/stable/c/b9a5d12cbdeb860306f8d47c92caee0ea6ee0e0a)
- [https://git.kernel.org/stable/c/d3355e0fdbbf531ca8b82a6a3feb80a1b7306a8b](https://git.kernel.org/stable/c/d3355e0fdbbf531ca8b82a6a3feb80a1b7306a8b)

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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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