Local kernel compromise via premature bitmap free
Published Jul 19, 2026 · Updated Jul 19, 2026
Use-after-free in the Linux Kernel IPv4 sysctl teardown allows local users to corrupt kernel memory during network namespace destruction. ipv4_sysctl_exit_net() frees net->ipv4.sysctl_local_reserved_ports before unregister_net_sysctl_table() prevents concurrent sysctl and socket access. An unprivileged local user can race namespace teardown against sysctl reads or writes, exposing freed heap data, overwriting kernel heap memory, or causing an oops or panic.
Summary
What happened
Use-after-free in the Linux Kernel IPv4 sysctl teardown allows local users to corrupt kernel memory during network namespace destruction. ipv4_sysctl_exit_net() frees net->ipv4.sysctl_local_reserved_ports before unregister_net_sysctl_table() prevents concurrent sysctl and socket access. An unprivileged local user can race namespace teardown against sysctl reads or writes, exposing freed heap data, overwriting kernel heap memory, or causing an oops or panic.
The record
- CVE
- CVE-2026-64002
- Published
- Jul 19, 2026
- Updated
- Jul 19, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux Kernel
- Classifications
- T1068
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Jul 19, 2026CVE publishedPublication date reported by the CVE source.
- 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.
- Affected versionversion=122ff243f5f104194750ecbc76d5946dd1eec934 <155f90be5ee8be5b110ebc0b7da33c54c83b0208
- Affected versionversion=122ff243f5f104194750ecbc76d5946dd1eec934 <5b23a2ff379e70b6b9ff744a972b63e1f8f4d996
- Affected versionversion=122ff243f5f104194750ecbc76d5946dd1eec934 <6512c57c4638ddec113bf42439361ba85a12048d
- Affected versionversion=122ff243f5f104194750ecbc76d5946dd1eec934 <87a1e0fe7776da7ab411be332b4be58ac8840d10
- Affected versionversion=122ff243f5f104194750ecbc76d5946dd1eec934 <8e59d4d0dcde2dfb07a7ef855c849a2a0560aa57
- Affected versionversion=122ff243f5f104194750ecbc76d5946dd1eec934 <a0ffc6081a8b27082dd5eae5aa1e3f59bbecf06c
- Affected versionversion=122ff243f5f104194750ecbc76d5946dd1eec934 <a7f4eefb6e1458431eef9fa20fb363320d185f76
- Affected versionversion=122ff243f5f104194750ecbc76d5946dd1eec934 <ecf45080a4d3f4526cacb8b14060fe3b49a6913b
- Affected versionversion=3.16
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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