Use-after-free via raced PPPoL2TP session access
Published Jun 25, 2026 · Updated Jun 25, 2026
Use-after-free in the Linux Kernel L2TP subsystem allows local users to dereference freed session memory through a raced PPPoL2TP ioctl. The pppol2tp_ioctl() path reads sk_user_data without locking or taking a session reference, then copy_from_user() can sleep while a concurrent close queues the session for deletion. The race requires low-privileged local access to issue the ioctl, delay the copy with a page fault, and close the socket before execution resumes.
Summary
What happened
Use-after-free in the Linux Kernel L2TP subsystem allows local users to dereference freed session memory through a raced PPPoL2TP ioctl. The pppol2tp_ioctl() path reads sk_user_data without locking or taking a session reference, then copy_from_user() can sleep while a concurrent close queues the session for deletion. The race requires low-privileged local access to issue the ioctl, delay the copy with a page fault, and close the socket before execution resumes.
The record
- CVE
- CVE-2026-53262
- Published
- Jun 25, 2026
- Updated
- Jun 25, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux Kernel
- Classifications
- T1068
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Jun 25, 2026CVE publishedPublication date reported by the CVE source.
- Jun 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?
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- Affected versionversion=2.6.35
- Affected versionversion=fd558d186df2c13a22455373858bae634a4795af <62f327e287cf7b595ae3f73ba72f5cd2a9e9f39f
- Affected versionversion=fd558d186df2c13a22455373858bae634a4795af <78cdfdca88cbf731a92f3b9ee5427c633dd94e28
- Affected versionversion=fd558d186df2c13a22455373858bae634a4795af <a213a8950414c684999dcf03edeea6c46ede172e
- Affected versionversion=fd558d186df2c13a22455373858bae634a4795af <e251d4cdfc725c9e7d686161e3b775a0e7d95053
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What is affected?
Published CVSS scores
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Attacks
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Weakness, pattern, technique
Public exploit references
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Technologies
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Your stack
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