Local process-data disclosure via privileged execve race
Published Jul 25, 2026 · Updated Jul 25, 2026
A TOCTOU race in Linux Kernel procfs allows local users to read process information across a privilege boundary during concurrent execve. The do_task_stat, proc_pid_wchan, proc_map_files_lookup, proc_map_files_readdir, proc_ns_get_link, and proc_ns_readlink paths call ptrace_may_access or obtain an mm without holding exec_update_lock, so access checks can span a privileged execve. Exploitation requires a local low-privileged process to win that race against a target executing a privileged image; the bounded impact is disclosure of procfs process data.
Summary
What happened
A TOCTOU race in Linux Kernel procfs allows local users to read process information across a privilege boundary during concurrent execve. The do_task_stat, proc_pid_wchan, proc_map_files_lookup, proc_map_files_readdir, proc_ns_get_link, and proc_ns_readlink paths call ptrace_may_access or obtain an mm without holding exec_update_lock, so access checks can span a privileged execve. Exploitation requires a local low-privileged process to win that race against a target executing a privileged image; the bounded impact is disclosure of procfs process data.
The record
- CVE
- CVE-2026-64371
- Published
- Jul 25, 2026
- Updated
- Jul 25, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux Kernel
- Classifications
- T1057
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Jul 25, 2026CVE publishedPublication date reported by the CVE source.
- Jul 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=2.6.27.23 <2.6.28
- Affected versionversion=2.6.29.3 <2.6.30
- Affected versionversion=2.6.30
- Affected versionversion=334ed22054b2ec8477e4409e214fc139cf937ef6
- Affected versionversion=6b06d6282100dd5aacf7d45443d651a1995bd9c4
- Affected versionversion=f83ce3e6b02d5e48b3a43b001390e2b58820389d <4bfe8c481846cee52473a2f7d7b30ee8e6749fc4
- Affected versionversion=f83ce3e6b02d5e48b3a43b001390e2b58820389d <6650527444dadc63d84aa939d14ecba4fadb2f69
- Affected versionversion=f83ce3e6b02d5e48b3a43b001390e2b58820389d <7456ae990a9738962b33146916fabca62ae3d4e0
- Affected versionversion=f83ce3e6b02d5e48b3a43b001390e2b58820389d <ae1e630bcaac739f625822078edbaea98366930d
- Affected versionversion=f83ce3e6b02d5e48b3a43b001390e2b58820389d <bb43679356f1f2a4c6b1c88aec4f021e5b5c74e9
- Affected versionversion=f83ce3e6b02d5e48b3a43b001390e2b58820389d <c1cfd63326f5d09999134e9052c353faf738286e
- Affected versionversion=f83ce3e6b02d5e48b3a43b001390e2b58820389d <d54f14655fd7d7b293698a8b6918563c4c0465e7
- Affected versionversion=f83ce3e6b02d5e48b3a43b001390e2b58820389d <f9b4b03ccc9c69bf7f7298d4559906ebea7143b3
What conditions does exploitation require?
What is affected?
Published CVSS scores
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Attacks
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Weakness, pattern, technique
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Technologies
Your stack
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Your stack
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