CVE-2026-64268Network attack vector

Remote kernel memory corruption via oversized Read Responses

Published Jul 25, 2026 · Updated Jul 25, 2026

Out-of-bounds write in the Linux Kernel siw receive path allows remote attackers to corrupt kernel memory via crafted Read Response segments. siw_proc_rresp() advances wqe->processed across continuation segments without bounding the cumulative offset against the validated sink length. A connected siw peer must answer an outstanding RREAD with DDP Last kept clear; the next siw_rx_data() placement writes beyond the sink buffer.

CVSS severity9.8
Critical
EPSS probability0.71%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Out-of-bounds write in the Linux Kernel siw receive path allows remote attackers to corrupt kernel memory via crafted Read Response segments. siw_proc_rresp() advances wqe->processed across continuation segments without bounding the cumulative offset against the validated sink length. A connected siw peer must answer an outstanding RREAD with DDP Last kept clear; the next siw_rx_data() placement writes beyond the sink buffer.

The record

CVE
CVE-2026-64268
Published
Jul 25, 2026
Updated
Jul 25, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
CWE-787, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jul 25, 2026CVE publishedPublication date reported by the CVE source.
  2. Jul 25, 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=5.3
  2. Affected versionversion=8b6a361b8c482f22ac99c3273285ff16b23fba91 <3ef7e052cbd05a8b13a51a07b185a39ec93ee1cf
  3. Affected versionversion=8b6a361b8c482f22ac99c3273285ff16b23fba91 <423a78ff7928c2601013f73ec6d896f5597d0df5
  4. Affected versionversion=8b6a361b8c482f22ac99c3273285ff16b23fba91 <595e6537ad1a210da32cbb9a7f91aa73090915ba
  5. Affected versionversion=8b6a361b8c482f22ac99c3273285ff16b23fba91 <6bc89f34a4597f9f6d41f7a60c67a3153bfe8851
  6. Affected versionversion=8b6a361b8c482f22ac99c3273285ff16b23fba91 <75c93cd3c421890f49ea93f0b978b9b7bb10e5e3
  7. Affected versionversion=8b6a361b8c482f22ac99c3273285ff16b23fba91 <7d29f7e9dbd844cae4d3e559cf78324b9642fd6b
  8. Affected versionversion=8b6a361b8c482f22ac99c3273285ff16b23fba91 <a31b6d18ded3cc32d9ee85a6ff0726d4274887b2
  9. Affected versionversion=8b6a361b8c482f22ac99c3273285ff16b23fba91 <b2e26c955f8dd7e8d3f16c858db05245ea4fa817

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=5.3; version=8b6a361b8c482f22ac99c3273285ff16b23fba91 <3ef7e052cbd05a8b13a51a07b185a39ec93ee1cf; version=8b6a361b8c482f22ac99c3273285ff16b23fba91 <423a78ff7928c2601013f73ec6d896f5597d0df5; version=8b6a361b8c482f22ac99c3273285ff16b23fba91 <595e6537ad1a210da32cbb9a7f91aa73090915ba; version=8b6a361b8c482f22ac99c3273285ff16b23fba91 <6bc89f34a4597f9f6d41f7a60c67a3153bfe8851; version=8b6a361b8c482f22ac99c3273285ff16b23fba91 <75c93cd3c421890f49ea93f0b978b9b7bb10e5e3; version=8b6a361b8c482f22ac99c3273285ff16b23fba91 <7d29f7e9dbd844cae4d3e559cf78324b9642fd6b; version=8b6a361b8c482f22ac99c3273285ff16b23fba91 <a31b6d18ded3cc32d9ee85a6ff0726d4274887b2; version=8b6a361b8c482f22ac99c3273285ff16b23fba91 <b2e26c955f8dd7e8d3f16c858db05245ea4fa817

Published CVSS scores

9.8Linux 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-787Out-of-bounds Write
T1190Exploit Public-Facing Application

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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