Process denial of service via timer truncation
Published Aug 15, 2026 · Updated Aug 15, 2026
Integer overflow in Linux kernel POSIX CPU timers allows local users to prematurely fire process CPU timers on 32-bit systems. The update_rlimit_cpu() function multiplies a 32-bit RLIMIT_CPU value by NSEC_PER_SEC before widening the result to u64, truncating limits above four seconds in the CPUCLOCK_PROF expiry cache. A local low-privileged user must operate on a 32-bit kernel and set a soft CPU limit of at least five seconds; enforcement remains correct, but premature timer expiry can interrupt the affected process.
Summary
What happened
Integer overflow in Linux kernel POSIX CPU timers allows local users to prematurely fire process CPU timers on 32-bit systems. The update_rlimit_cpu() function multiplies a 32-bit RLIMIT_CPU value by NSEC_PER_SEC before widening the result to u64, truncating limits above four seconds in the CPUCLOCK_PROF expiry cache. A local low-privileged user must operate on a 32-bit kernel and set a soft CPU limit of at least five seconds; enforcement remains correct, but premature timer expiry can interrupt the affected process.
The record
- CVE
- CVE-2026-72068
- Published
- Aug 15, 2026
- Updated
- Aug 15, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- CWE-190, T1499
- 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=4.11
- Affected versionversion=858cf3a8c59968e7c5f7c1a1192459a0d52d1ab4 <1fafc4d9b411645eb34de43362b966dc8fb3e263
- Affected versionversion=858cf3a8c59968e7c5f7c1a1192459a0d52d1ab4 <26aff38fefb1d6cd87e22525f41cc8f1aa61b24f
- Affected versionversion=858cf3a8c59968e7c5f7c1a1192459a0d52d1ab4 <384628d6cdde0fcd76868606fad3ad8293100afb
- Affected versionversion=858cf3a8c59968e7c5f7c1a1192459a0d52d1ab4 <571e1f10b5996ba3e4dc63ea77de4aa309c384ce
- Affected versionversion=858cf3a8c59968e7c5f7c1a1192459a0d52d1ab4 <cff8281bacd2866767e6194c3079d33b6c5a74f4
- Affected versionversion=858cf3a8c59968e7c5f7c1a1192459a0d52d1ab4 <ea6a188ee805e841a0e242f14d15953e0dfa74bb
- Affected versionversion=858cf3a8c59968e7c5f7c1a1192459a0d52d1ab4 <edf6babb9edd2d3e19229ade339081f439d4f478
- Affected versionversion=858cf3a8c59968e7c5f7c1a1192459a0d52d1ab4 <feb5c87c8514444ba891b75a5a3eae57c64edaf8
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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Public exploit references
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Technologies
Your stack
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Your stack
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