Kernel memory disclosure via uncleared Netlink padding
Published Jul 27, 2026 · Updated Jul 27, 2026
Information disclosure in the psample subsystem of Linux Kernel allows local users to read kernel memory bytes through Netlink messages. In net/psample/psample.c, the PSAMPLE_ATTR_DATA builder open-codes nla_put(), copies packet data, and leaves four-byte alignment padding uncleared. A low-privileged local user must receive psample multicast traffic whose sampled data length is not divisible by four; each qualifying attribute exposes one to three padding bytes.
Summary
What happened
Information disclosure in the psample subsystem of Linux Kernel allows local users to read kernel memory bytes through Netlink messages. In net/psample/psample.c, the PSAMPLE_ATTR_DATA builder open-codes nla_put(), copies packet data, and leaves four-byte alignment padding uncleared. A low-privileged local user must receive psample multicast traffic whose sampled data length is not divisible by four; each qualifying attribute exposes one to three padding bytes.
The record
- CVE
- CVE-2026-64553
- Published
- Jul 27, 2026
- Updated
- Jul 27, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux Kernel
- Classifications
- T1005
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Jul 27, 2026CVE publishedPublication date reported by the CVE source.
- Jul 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.
- Affected versionversion=4.11
- Affected versionversion=6ae0a6286171154661b74f7f550f9441c6008424 <0d3ea2ccddda442077fc44f11d873209c97ec50b
- Affected versionversion=6ae0a6286171154661b74f7f550f9441c6008424 <48930f6c59fd0056c2de46ce52bfe27d9c9e5eb6
- Affected versionversion=6ae0a6286171154661b74f7f550f9441c6008424 <794a0d8bdbb39e083ed42caccb86d687a9b53570
- Affected versionversion=6ae0a6286171154661b74f7f550f9441c6008424 <7fe7e6949964aa8ee6305f09db2dc9eede977bb3
- Affected versionversion=6ae0a6286171154661b74f7f550f9441c6008424 <a6cfb924ad74efce254e99c197d2e3863de70868
- Affected versionversion=6ae0a6286171154661b74f7f550f9441c6008424 <aedd02af1f8b0bceb7f42f5a21c41634ca9ed390
- Affected versionversion=6ae0a6286171154661b74f7f550f9441c6008424 <befe1ebe7fc2c65c80074bc34ceeb0a721ed3cd2
- Affected versionversion=6ae0a6286171154661b74f7f550f9441c6008424 <e2fa322782a2d7d8078f7bb20817e0aa9f7c32e9
What conditions does exploitation require?
What is affected?
Published CVSS scores
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Attacks
What attackers are doing with it
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Weakness, pattern, technique
Public exploit references
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Technologies
Your stack
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Your stack
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