Out-of-bounds kernel access via stale scan bounds
Published Sep 11, 2026 · Updated Sep 11, 2026
Out-of-bounds access in Linux zram 5.0 allows local users to access slots beyond the active table by racing reinitialization with writeback. writeback_store reads zram->disksize before taking dev_lock, so a reset to a smaller table leaves the pending scan with the old upper bound. Reaching the race requires privileged local control of zram reset, disksize, backing-storage, and writeback interfaces; no further consequence is published.
Summary
What happened
Out-of-bounds access in Linux zram 5.0 allows local users to access slots beyond the active table by racing reinitialization with writeback. writeback_store reads zram->disksize before taking dev_lock, so a reset to a smaller table leaves the pending scan with the old upper bound. Reaching the race requires privileged local control of zram reset, disksize, backing-storage, and writeback interfaces; no further consequence is published.
The record
- CVE
- CVE-2026-89718
- Published
- Sep 11, 2026
- Updated
- Sep 11, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- Unavailable
- Attack vector
- local
- Privileges
- admin
Timeline
How it unfolded
- Sep 11, 2026CVE publishedPublication date reported by the CVE source.
- Sep 11, 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=5.0
- Affected versionversion=a939888ec38bf1f33e4a903056677e92a4844244 <07a82a66f8c1894d92e51d97542c32ebf2c51b09
- Affected versionversion=a939888ec38bf1f33e4a903056677e92a4844244 <894913e2d35c46ff19a77530907771ae57862b96
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
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Public exploit references
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Technologies
Your stack
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Your stack
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