Local privilege escalation via KCM callback race
Published Aug 15, 2026 · Updated Aug 15, 2026
Race condition in the Linux kernel 4.6 and later allows local users to corrupt kernel memory through concurrent KCM socket operations. The kcm_attach() and kcm_unattach() paths update live TCP callback pointers with plain stores while other CPUs can read and invoke them. Low-privileged local access and concurrent attach, detach, and network activity are required; a stale callback can disclose or corrupt kernel data, crash the kernel, or elevate privileges.
Summary
What happened
Race condition in the Linux kernel 4.6 and later allows local users to corrupt kernel memory through concurrent KCM socket operations. The kcm_attach() and kcm_unattach() paths update live TCP callback pointers with plain stores while other CPUs can read and invoke them. Low-privileged local access and concurrent attach, detach, and network activity are required; a stale callback can disclose or corrupt kernel data, crash the kernel, or elevate privileges.
The record
- CVE
- CVE-2026-74262
- Published
- Aug 15, 2026
- Updated
- Aug 15, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- CWE-362, CAPEC-26, T1068
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Aug 15, 2026CVE publishedPublication date reported by the CVE source.
- Aug 15, 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?
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- Affected versionversion=4.6
- Affected versionversion=ab7ac4eb9832e32a09f4e8042705484d2fb0aad3 <0cb3e2f40679032c1aa2186280a86e5ead0161ee
- Affected versionversion=ab7ac4eb9832e32a09f4e8042705484d2fb0aad3 <11faefd11ce2448bac7279ab302dd1954a6547fe
- Affected versionversion=ab7ac4eb9832e32a09f4e8042705484d2fb0aad3 <47186409c092cd7dd70350999186c700233e854d
- Affected versionversion=ab7ac4eb9832e32a09f4e8042705484d2fb0aad3 <9684fff87124b201e11dea01ded9173025359a0f
- Affected versionversion=ab7ac4eb9832e32a09f4e8042705484d2fb0aad3 <b4ccd6eef671d7c44a30123cd29f3acf3de8468e
- Affected versionversion=ab7ac4eb9832e32a09f4e8042705484d2fb0aad3 <b8c90823cdfb5f3d22f261aeb3e9066612853c36
- Affected versionversion=ab7ac4eb9832e32a09f4e8042705484d2fb0aad3 <f01fb6138f8eb606b56ce9158e2d8b72352c53f4
- Affected versionversion=ab7ac4eb9832e32a09f4e8042705484d2fb0aad3 <fa26e4606aed0f7fe793c325506adeda1d847a43
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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