CVE-2026-64121

Adjacent slab disclosure via mismatched queue counts

Published Jul 19, 2026 · Updated Jul 19, 2026

Out-of-bounds read in the Linux Kernel IFB driver allows local users to disclose adjacent kernel slab data through an ethtool stats request. ifb_dev_init allocates tx_private for num_tx_queues entries, but ifb_get_ethtool_stats walks it using larger real queue counts and returns bytes beyond the allocation through ETHTOOL_GSTATS. Low-privileged local access and an IFB device with more receive than transmit queues are required; the read exposes adjacent slab data without reported modification.

CVSS severity7.1
High
EPSS probability0.13%
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 the Linux Kernel IFB driver allows local users to disclose adjacent kernel slab data through an ethtool stats request. ifb_dev_init allocates tx_private for num_tx_queues entries, but ifb_get_ethtool_stats walks it using larger real queue counts and returns bytes beyond the allocation through ETHTOOL_GSTATS. Low-privileged local access and an IFB device with more receive than transmit queues are required; the read exposes adjacent slab data without reported modification.

The record

CVE
CVE-2026-64121
Published
Jul 19, 2026
Updated
Jul 19, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
CWE-125
Attack vector
local
Privileges
authenticated

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=5.17
  2. Affected versionversion=a21ee5b2fcb8d6d3973446c5039e966c4cfe40d1 <16bd798cb6d8337d7c3eea1adc412f31b5181d5b
  3. Affected versionversion=a21ee5b2fcb8d6d3973446c5039e966c4cfe40d1 <2638e1773904d7aa8f24c6e7fda2ed7d69df6fa4
  4. Affected versionversion=a21ee5b2fcb8d6d3973446c5039e966c4cfe40d1 <301a554e458e2f5ec47f2c336a7cb03b877f9fd6
  5. Affected versionversion=a21ee5b2fcb8d6d3973446c5039e966c4cfe40d1 <5db89c99566fc4728cc92e941d8e1975711e24b5
  6. Affected versionversion=a21ee5b2fcb8d6d3973446c5039e966c4cfe40d1 <6afdb8113cb007f9332f59a9b7fd45731b8a9de5
  7. Affected versionversion=a21ee5b2fcb8d6d3973446c5039e966c4cfe40d1 <f8a5a76b4a683043c6eff2a060bcaa17f9316ad5

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=5.17; version=a21ee5b2fcb8d6d3973446c5039e966c4cfe40d1 <16bd798cb6d8337d7c3eea1adc412f31b5181d5b; version=a21ee5b2fcb8d6d3973446c5039e966c4cfe40d1 <2638e1773904d7aa8f24c6e7fda2ed7d69df6fa4; version=a21ee5b2fcb8d6d3973446c5039e966c4cfe40d1 <301a554e458e2f5ec47f2c336a7cb03b877f9fd6; version=a21ee5b2fcb8d6d3973446c5039e966c4cfe40d1 <5db89c99566fc4728cc92e941d8e1975711e24b5; version=a21ee5b2fcb8d6d3973446c5039e966c4cfe40d1 <6afdb8113cb007f9332f59a9b7fd45731b8a9de5; version=a21ee5b2fcb8d6d3973446c5039e966c4cfe40d1 <f8a5a76b4a683043c6eff2a060bcaa17f9316ad5

Published CVSS scores

7.1NIST NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

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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-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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