Kernel crash via cad_pid lifetime race
Published Sep 25, 2026 · Updated Sep 25, 2026
Use-after-free in the Linux kernel allows local users to crash the kernel by racing reads and writes of the cad_pid sysctl. proc_do_cad_pid() and kill_cad_pid() dereference a shared struct pid after a concurrent writer replaces it and releases its final reference. At report time, user and PID namespaces exposed the sysctl to unprivileged users; successful exploitation causes a kernel service interrupt.
Summary
What happened
Use-after-free in the Linux kernel allows local users to crash the kernel by racing reads and writes of the cad_pid sysctl. proc_do_cad_pid() and kill_cad_pid() dereference a shared struct pid after a concurrent writer replaces it and releases its final reference. At report time, user and PID namespaces exposed the sysctl to unprivileged users; successful exploitation causes a kernel service interrupt.
The record
- CVE
- CVE-2026-97938
- Published
- Sep 25, 2026
- Updated
- Sep 25, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- T1499
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Sep 25, 2026CVE publishedPublication date reported by the CVE source.
- Sep 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?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=2.6.19
- Affected versionversion=9ec52099e4b8678a60e9f93e41ad87885d64f3e6 <5a88f78df753993469dab4d1831f8fb4256a9468
- Affected versionversion=9ec52099e4b8678a60e9f93e41ad87885d64f3e6 <9a17b0e053197a6a42cdc75e75a35b17aa662088
- Affected versionversion=9ec52099e4b8678a60e9f93e41ad87885d64f3e6 <ad72e2566643fff7f01666d845fb026898155e1f
What conditions does exploitation require?
What is affected?
Published CVSS scores
No CVSS assessment is available in this record.
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Attacks
What attackers are doing with it
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Activity data is delayed. The latest report is Sep 28, 2026.
Weakness, pattern, technique
Public exploit references
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Technologies
Your stack
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Your stack
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