CVE-2026-64056Network attack vector

Remote kernel corruption via cross-port RX race

Published Jul 19, 2026 · Updated Jul 19, 2026

Race condition in the Cortina Ethernet driver in Linux Kernel allows remote attackers to corrupt kernel memory via Gemini GMAC traffic. gmac_rx() stores the fragment-assembly SKB in a static local pointer shared by both ports, allowing concurrent NAPI receive paths to update, submit, or free the same state without synchronization. Exploitation requires two active Gemini Ethernet ports and overlapping fragmented or jumbo-frame processing; corruption enables memory disclosure, writes, code execution, or a kernel panic.

CVSS severity9.8
Critical
EPSS probability0.55%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Race condition in the Cortina Ethernet driver in Linux Kernel allows remote attackers to corrupt kernel memory via Gemini GMAC traffic. gmac_rx() stores the fragment-assembly SKB in a static local pointer shared by both ports, allowing concurrent NAPI receive paths to update, submit, or free the same state without synchronization. Exploitation requires two active Gemini Ethernet ports and overlapping fragmented or jumbo-frame processing; corruption enables memory disclosure, writes, code execution, or a kernel panic.

The record

CVE
CVE-2026-64056
Published
Jul 19, 2026
Updated
Jul 19, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
CWE-820, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jul 19, 2026CVE publishedPublication date reported by the CVE source.
  2. Jul 19, 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=4.16
  2. Affected versionversion=4d5ae32f5e1e13f7f36d6439ec3257993b9f5b88 <06937db21ee311ed07eba47954447245041a982d
  3. Affected versionversion=4d5ae32f5e1e13f7f36d6439ec3257993b9f5b88 <27856d533eca3804008695f61c1e4d5ff984196b
  4. Affected versionversion=4d5ae32f5e1e13f7f36d6439ec3257993b9f5b88 <3b249988d774dacf13b203817e971934a42243c4
  5. Affected versionversion=4d5ae32f5e1e13f7f36d6439ec3257993b9f5b88 <67a35e7da7ef9d2f000aa758552a128324c604a0
  6. Affected versionversion=4d5ae32f5e1e13f7f36d6439ec3257993b9f5b88 <6bba24e9ebe6f1c0b356cd471e36bdc7fa434897
  7. Affected versionversion=4d5ae32f5e1e13f7f36d6439ec3257993b9f5b88 <72158ea185b27afae163949b0e86164cb6b64e55
  8. Affected versionversion=4d5ae32f5e1e13f7f36d6439ec3257993b9f5b88 <b6b22824b30e48ce1df3a2e80990f4b8505deb50
  9. Affected versionversion=4d5ae32f5e1e13f7f36d6439ec3257993b9f5b88 <cfd62907f3cdbc3b6da8f49ba907c0390018fe5e

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=4.16; version=4d5ae32f5e1e13f7f36d6439ec3257993b9f5b88 <06937db21ee311ed07eba47954447245041a982d; version=4d5ae32f5e1e13f7f36d6439ec3257993b9f5b88 <27856d533eca3804008695f61c1e4d5ff984196b; version=4d5ae32f5e1e13f7f36d6439ec3257993b9f5b88 <3b249988d774dacf13b203817e971934a42243c4; version=4d5ae32f5e1e13f7f36d6439ec3257993b9f5b88 <67a35e7da7ef9d2f000aa758552a128324c604a0; version=4d5ae32f5e1e13f7f36d6439ec3257993b9f5b88 <6bba24e9ebe6f1c0b356cd471e36bdc7fa434897; version=4d5ae32f5e1e13f7f36d6439ec3257993b9f5b88 <72158ea185b27afae163949b0e86164cb6b64e55; version=4d5ae32f5e1e13f7f36d6439ec3257993b9f5b88 <b6b22824b30e48ce1df3a2e80990f4b8505deb50; version=4d5ae32f5e1e13f7f36d6439ec3257993b9f5b88 <cfd62907f3cdbc3b6da8f49ba907c0390018fe5e

Published CVSS scores

9.8Linux kernel CNACVSS:3.1/AV:N/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.

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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)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-820Missing Synchronization
T1499.004Application or System Exploitation

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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