CVE-2026-90399

Kernel memory corruption via short firmware TLVs

Published Sep 17, 2026 · Updated Sep 18, 2026

Heap buffer overflow in the ath12k Wi-Fi driver in Linux allows attackers to corrupt kernel memory through short firmware TLVs. ath12k_wmi_mac_phy_caps_parse allocates mac_phy_caps with a firmware-clamped element length, but memcpy advances each destination by the full structure size, so later slots exceed the allocation. Compromised or malicious WCN7850 or QCN9274 firmware triggers the write during probe or crash recovery without a Linux account or user interaction, enabling adjacent-object corruption, kernel control-flow hijacking, or a host panic.

CVSS severity8.4
High
EPSS probability0.18%
Next 30 days · Oct 19, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Get started

Summary

What happened

Heap buffer overflow in the ath12k Wi-Fi driver in Linux allows attackers to corrupt kernel memory through short firmware TLVs. ath12k_wmi_mac_phy_caps_parse allocates mac_phy_caps with a firmware-clamped element length, but memcpy advances each destination by the full structure size, so later slots exceed the allocation. Compromised or malicious WCN7850 or QCN9274 firmware triggers the write during probe or crash recovery without a Linux account or user interaction, enabling adjacent-object corruption, kernel control-flow hijacking, or a host panic.

The record

CVE
CVE-2026-90399
Published
Sep 17, 2026
Updated
Sep 18, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1068
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. Sep 17, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 18, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=6.3
  2. Affected versionversion=d889913205cf7ebda905b1e62c5867ed4e39f6c2 <26f8f87f0a556e7984366c64cebc16d49e15d22f
  3. Affected versionversion=d889913205cf7ebda905b1e62c5867ed4e39f6c2 <4c6eb712a91fa079be6f9f1419c96e0ad2227081
  4. Affected versionversion=d889913205cf7ebda905b1e62c5867ed4e39f6c2 <b9a5d12cbdeb860306f8d47c92caee0ea6ee0e0a
  5. Affected versionversion=d889913205cf7ebda905b1e62c5867ed4e39f6c2 <d3355e0fdbbf531ca8b82a6a3feb80a1b7306a8b

What conditions does exploitation require?

Attack vectorlocal
Required privilegesunauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=6.3; version=d889913205cf7ebda905b1e62c5867ed4e39f6c2 <26f8f87f0a556e7984366c64cebc16d49e15d22f; version=d889913205cf7ebda905b1e62c5867ed4e39f6c2 <4c6eb712a91fa079be6f9f1419c96e0ad2227081; version=d889913205cf7ebda905b1e62c5867ed4e39f6c2 <b9a5d12cbdeb860306f8d47c92caee0ea6ee0e0a; version=d889913205cf7ebda905b1e62c5867ed4e39f6c2 <d3355e0fdbbf531ca8b82a6a3feb80a1b7306a8b

Published CVSS scores

8.4LinuxCVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Activity data is delayed. The latest report is Sep 28, 2026.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 22, 2026Sep 28, 2026
Latest reporting daySep 28, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1068Exploitation for Privilege Escalation

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Get started to see how Hinoki identifies affected software and validates exploitability in your environment.

Get started