CVE-2026-64102Network attack vector

Kernel memory over-read via iWARP length underflow

Published Jul 19, 2026 · Updated Jul 19, 2026

Out-of-bounds read in Linux Kernel allows remote attackers to trigger a multi-gigabyte kernel read via a malformed iWARP FPDU. In siw_tcp_rx_data(), an MPA length below the opcode header size becomes negative, passes siw_check_mem(), and is promoted to a huge skb_copy_bits() length. An established TCP connection to a host actively using the siw stack is required; the demonstrated result is a KASAN-detected use-after-free and 4 GiB read.

CVSS severity9.8
Critical
EPSS probability0.50%
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 read in Linux Kernel allows remote attackers to trigger a multi-gigabyte kernel read via a malformed iWARP FPDU. In siw_tcp_rx_data(), an MPA length below the opcode header size becomes negative, passes siw_check_mem(), and is promoted to a huge skb_copy_bits() length. An established TCP connection to a host actively using the siw stack is required; the demonstrated result is a KASAN-detected use-after-free and 4 GiB read.

The record

CVE
CVE-2026-64102
Published
Jul 19, 2026
Updated
Jul 19, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
CWE-125
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=5.3
  2. Affected versionversion=8b6a361b8c482f22ac99c3273285ff16b23fba91 <0ce1bc9e46ecabe84772bb561e373c0d9876d6f2
  3. Affected versionversion=8b6a361b8c482f22ac99c3273285ff16b23fba91 <1012896f4225e8f801ff3c1648023845b66dfb11
  4. Affected versionversion=8b6a361b8c482f22ac99c3273285ff16b23fba91 <14553be882d9ce91749c9d64041de66e34ad8e70
  5. Affected versionversion=8b6a361b8c482f22ac99c3273285ff16b23fba91 <33a8b5e971e294ec2a7b74211c545e09efd8e9ac
  6. Affected versionversion=8b6a361b8c482f22ac99c3273285ff16b23fba91 <4a331582011d9e8089af8aa2a61ec6b4443bb245
  7. Affected versionversion=8b6a361b8c482f22ac99c3273285ff16b23fba91 <683f7cfbf514193d63c0efa079f3352bde84c2e0
  8. Affected versionversion=8b6a361b8c482f22ac99c3273285ff16b23fba91 <775b4dc9618a99a1fa48b57554041a5dc17e1336
  9. Affected versionversion=8b6a361b8c482f22ac99c3273285ff16b23fba91 <c7c0c0f4379dedec12d24dbb9dded5d2db7fd9f2

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=5.3; version=8b6a361b8c482f22ac99c3273285ff16b23fba91 <0ce1bc9e46ecabe84772bb561e373c0d9876d6f2; version=8b6a361b8c482f22ac99c3273285ff16b23fba91 <1012896f4225e8f801ff3c1648023845b66dfb11; version=8b6a361b8c482f22ac99c3273285ff16b23fba91 <14553be882d9ce91749c9d64041de66e34ad8e70; version=8b6a361b8c482f22ac99c3273285ff16b23fba91 <33a8b5e971e294ec2a7b74211c545e09efd8e9ac; version=8b6a361b8c482f22ac99c3273285ff16b23fba91 <4a331582011d9e8089af8aa2a61ec6b4443bb245; version=8b6a361b8c482f22ac99c3273285ff16b23fba91 <683f7cfbf514193d63c0efa079f3352bde84c2e0; version=8b6a361b8c482f22ac99c3273285ff16b23fba91 <775b4dc9618a99a1fa48b57554041a5dc17e1336; version=8b6a361b8c482f22ac99c3273285ff16b23fba91 <c7c0c0f4379dedec12d24dbb9dded5d2db7fd9f2

Published CVSS scores

9.8kernel.orgCVSS: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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-125Out-of-bounds Read

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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