CVE-2026-43457

Local service interruption via leaked receive buffers

Published May 8, 2026 · Updated May 8, 2026

Memory leakage in the MCTP-over-I2C receive path in the Linux Kernel allows local users to exhaust memory and interrupt service. In drivers/net/mctp/mctp-i2c.c, the receive path allocates an skb but bypasses netif_rx without freeing it when midev->allow_rx is false. Exploitation requires low-privilege local access and an enabled MCTP-over-I2C device reaching that disabled-reception path; the reported consequence is limited to availability.

CVSS severity5.5
Medium
EPSS probability0.11%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Memory leakage in the MCTP-over-I2C receive path in the Linux Kernel allows local users to exhaust memory and interrupt service. In drivers/net/mctp/mctp-i2c.c, the receive path allocates an skb but bypasses netif_rx without freeing it when midev->allow_rx is false. Exploitation requires low-privilege local access and an enabled MCTP-over-I2C device reaching that disabled-reception path; the reported consequence is limited to availability.

The record

CVE
CVE-2026-43457
Published
May 8, 2026
Updated
May 8, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
CWE-401, T1499
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. May 8, 2026CVE publishedPublication date reported by the CVE source.
  2. May 8, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

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

  1. Affected versionversion=5.18
  2. Affected versionversion=f5b8abf9fc3dacd7529d363e26fe8230935d65f8 <0fb2adbdd5c03e8c9ebcdc48afd414b2724c85eb
  3. Affected versionversion=f5b8abf9fc3dacd7529d363e26fe8230935d65f8 <1b1be322342a6b0085bf6ee52235e5ac9834ec25
  4. Affected versionversion=f5b8abf9fc3dacd7529d363e26fe8230935d65f8 <1ec54187e1aa40a4cfa2b265e9a311179f24b98d
  5. Affected versionversion=f5b8abf9fc3dacd7529d363e26fe8230935d65f8 <9f81be2ab9d8e4744871bfb3e868ef413413829f
  6. Affected versionversion=f5b8abf9fc3dacd7529d363e26fe8230935d65f8 <d7900a43b0a314a645ca0a2adf45928dbc7001f4
  7. Affected versionversion=f5b8abf9fc3dacd7529d363e26fe8230935d65f8 <e3f5e0f22cfc2371e7471c9fd5b4da78f9df7c69

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=5.18; version=f5b8abf9fc3dacd7529d363e26fe8230935d65f8 <0fb2adbdd5c03e8c9ebcdc48afd414b2724c85eb; version=f5b8abf9fc3dacd7529d363e26fe8230935d65f8 <1b1be322342a6b0085bf6ee52235e5ac9834ec25; version=f5b8abf9fc3dacd7529d363e26fe8230935d65f8 <1ec54187e1aa40a4cfa2b265e9a311179f24b98d; version=f5b8abf9fc3dacd7529d363e26fe8230935d65f8 <9f81be2ab9d8e4744871bfb3e868ef413413829f; version=f5b8abf9fc3dacd7529d363e26fe8230935d65f8 <d7900a43b0a314a645ca0a2adf45928dbc7001f4; version=f5b8abf9fc3dacd7529d363e26fe8230935d65f8 <e3f5e0f22cfc2371e7471c9fd5b4da78f9df7c69

Published CVSS scores

5.5NIST NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/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.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-401Missing Release of Memory after Effective Lifetime
T1499Endpoint Denial of Service

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

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Your stack

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