CVE-2026-45940

Kernel crash via incorrect receive-descriptor length

Published May 27, 2026 · Updated May 27, 2026

Denial of service in the Linux Kernel GMAC4 stmmac receive path allows local users to crash the kernel during packet processing. When split-header mode leaves the first descriptor's buf2 partly empty, stmmac_napi_poll_rx assumes it is full and miscalculates the second descriptor's length. The flaw requires GMAC4 with split headers enabled, and the resulting invalid DMA synchronization address causes a kernel oops and service interruption.

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

What happened

Denial of service in the Linux Kernel GMAC4 stmmac receive path allows local users to crash the kernel during packet processing. When split-header mode leaves the first descriptor's buf2 partly empty, stmmac_napi_poll_rx assumes it is full and miscalculates the second descriptor's length. The flaw requires GMAC4 with split headers enabled, and the resulting invalid DMA synchronization address causes a kernel oops and service interruption.

The record

CVE
CVE-2026-45940
Published
May 27, 2026
Updated
May 27, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
T1499
Attack vector
local
Privileges
authenticated

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

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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=5.4
  2. Affected versionversion=ec222003bd948de8f3ffbca522d328af1a8452ad <36f81cb7d82e9614a7058da6abdf2e3a03993df1
  3. Affected versionversion=ec222003bd948de8f3ffbca522d328af1a8452ad <b1f23df09e7dbf4c86b6908dff7efb8cb2b7d609
  4. Affected versionversion=ec222003bd948de8f3ffbca522d328af1a8452ad <babab1b42ed68877ef669a08384becf281ad2582

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=5.4; version=ec222003bd948de8f3ffbca522d328af1a8452ad <36f81cb7d82e9614a7058da6abdf2e3a03993df1; version=ec222003bd948de8f3ffbca522d328af1a8452ad <b1f23df09e7dbf4c86b6908dff7efb8cb2b7d609; version=ec222003bd948de8f3ffbca522d328af1a8452ad <babab1b42ed68877ef669a08384becf281ad2582

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

T1499Endpoint Denial of Service

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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