CVE-2026-90416Hinoki check available

Stack disclosure via oversized debugfs read length

Published Sep 17, 2026 · Updated Sep 17, 2026

An out-of-bounds read in Linux mlx5 debugfs allows local users to read one byte of kernel stack data through congestion-parameter reads. In get_param(), signed formatting of a u32 value such as 0x80000000 truncates the output in an 11-byte buffer, but snprintf() returns 12 and simple_read_from_buffer() copies one byte beyond it. Access requires the owner-only cc_params debugfs files on a capable mlx5 device; the demonstrated operation discloses data rather than modifying kernel memory.

CVSS severity2.3
Low
EPSS probability0.21%
Next 30 days · Oct 19, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Get started

Summary

What happened

An out-of-bounds read in Linux mlx5 debugfs allows local users to read one byte of kernel stack data through congestion-parameter reads. In get_param(), signed formatting of a u32 value such as 0x80000000 truncates the output in an 11-byte buffer, but snprintf() returns 12 and simple_read_from_buffer() copies one byte beyond it. Access requires the owner-only cc_params debugfs files on a capable mlx5 device; the demonstrated operation discloses data rather than modifying kernel memory.

The record

CVE
CVE-2026-90416
Published
Sep 17, 2026
Updated
Sep 17, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
Unavailable
Attack vector
local
Privileges
admin

Timeline

How it unfolded

  1. Sep 17, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 17, 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=4.14
  2. Affected versionversion=4a2da0b8c0782816f3ae6846ae7942fcbb0f8172 <03826bc1fa6c90405bf05831f2b501a8368dcd27
  3. Affected versionversion=4a2da0b8c0782816f3ae6846ae7942fcbb0f8172 <06b62758f81e27ca4c81201c22e3436c6d9ac894
  4. Affected versionversion=4a2da0b8c0782816f3ae6846ae7942fcbb0f8172 <0b0122fcc923a0271130f5fb71af2cd7e20434d9
  5. Affected versionversion=4a2da0b8c0782816f3ae6846ae7942fcbb0f8172 <1c5b4f76cd73372c5a8a4c91c95d5a31f141e091
  6. Affected versionversion=4a2da0b8c0782816f3ae6846ae7942fcbb0f8172 <4599311e78e88c893ad551aca622de2bfdf1c31f
  7. Affected versionversion=4a2da0b8c0782816f3ae6846ae7942fcbb0f8172 <c75ee076fa09778a2f9602a972dade4a0b0785f7
  8. Affected versionversion=4a2da0b8c0782816f3ae6846ae7942fcbb0f8172 <ce8dfd32a33b578c3abf178f67b4c8d36854f041
  9. Affected versionversion=4a2da0b8c0782816f3ae6846ae7942fcbb0f8172 <d809cf3f0ed9255abfc73c4730bcf187151422af

What conditions does exploitation require?

Attack vectorlocal
Required privilegesadmin

What is affected?

The Linux Kernel Organization · Linuxversion=4.14; version=4a2da0b8c0782816f3ae6846ae7942fcbb0f8172 <03826bc1fa6c90405bf05831f2b501a8368dcd27; version=4a2da0b8c0782816f3ae6846ae7942fcbb0f8172 <06b62758f81e27ca4c81201c22e3436c6d9ac894; version=4a2da0b8c0782816f3ae6846ae7942fcbb0f8172 <0b0122fcc923a0271130f5fb71af2cd7e20434d9; version=4a2da0b8c0782816f3ae6846ae7942fcbb0f8172 <1c5b4f76cd73372c5a8a4c91c95d5a31f141e091; version=4a2da0b8c0782816f3ae6846ae7942fcbb0f8172 <4599311e78e88c893ad551aca622de2bfdf1c31f; version=4a2da0b8c0782816f3ae6846ae7942fcbb0f8172 <c75ee076fa09778a2f9602a972dade4a0b0785f7; version=4a2da0b8c0782816f3ae6846ae7942fcbb0f8172 <ce8dfd32a33b578c3abf178f67b4c8d36854f041; version=4a2da0b8c0782816f3ae6846ae7942fcbb0f8172 <d809cf3f0ed9255abfc73c4730bcf187151422af

Published CVSS scores

2.3Amazon LinuxCVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:L/I:N/A:N
2.3SUSECVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:L/I:N/A:N

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
Privilegesadmin
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

No sourced classifications are available.

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