CVE-2026-46064

Kernel heap disclosure via inflated dot-command lengths

Published May 27, 2026 · Updated May 27, 2026

Out-of-bounds read in the Linux Kernel ibmasm driver allows local users with root access to disclose adjacent kernel heap data. The ibmasm_send_i2o_message() function trusts command_size and data_size from a user-written dot_command_header when sizing memcpy_toio(), so a small allocation triggers an over-read of about 65 KB. Exploitation requires root access and an active ibmasm service-processor path; leaked heap bytes are forwarded to the service processor over MMIO, and an inconsistent frame can desynchronize it.

CVSS severity7.1
High
EPSS probability0.14%
Next 30 days · Sep 16, 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.

Book a demo

Summary

What happened

Out-of-bounds read in the Linux Kernel ibmasm driver allows local users with root access to disclose adjacent kernel heap data. The ibmasm_send_i2o_message() function trusts command_size and data_size from a user-written dot_command_header when sizing memcpy_toio(), so a small allocation triggers an over-read of about 65 KB. Exploitation requires root access and an active ibmasm service-processor path; leaked heap bytes are forwarded to the service processor over MMIO, and an inconsistent frame can desynchronize it.

The record

CVE
CVE-2026-46064
Published
May 27, 2026
Updated
May 27, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
CWE-125, T1005
Attack vector
local
Privileges
admin

Timeline

How it unfolded

  1. May 27, 2026CVE publishedPublication date reported by the CVE source.
  2. May 27, 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=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <9aad71144fa3682cca3837a06c8623016790e7ec
  2. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <9e8f6c9d4ecddda2f28baa1678340286cff3969c
  3. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <c1c2417c60dbdca5ebb00462f21ee71c2d7f7083
  4. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <fd19eb1c75047a4ed4e855f56cafd704dc3914e0
  5. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <fe31722b0194ff76bf8b461e8bf97a2081147787
  6. Affected versionversion=2.6.12

What conditions does exploitation require?

Attack vectorlocal
Required privilegesadmin

What is affected?

The Linux Kernel Organization · Linux Kernelversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <9aad71144fa3682cca3837a06c8623016790e7ec; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <9e8f6c9d4ecddda2f28baa1678340286cff3969c; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <c1c2417c60dbdca5ebb00462f21ee71c2d7f7083; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <fd19eb1c75047a4ed4e855f56cafd704dc3914e0; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <fe31722b0194ff76bf8b461e8bf97a2081147787; version=2.6.12

Published CVSS scores

7.1NIST NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/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.

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

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesadmin
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-125Out-of-bounds Read
T1005Data from Local System

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

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo