Data loss via stale memfd folio dirty state
Published May 8, 2026 · Updated May 8, 2026
Data loss in Linux Kernel 6.19 allows local users to discard memfd contents during a live update under memory pressure. The memfd_luo preservation path serializes a folio's dirty state at preserve time even though mapped pages can become dirty later, so retrieval can restore user data as clean and reclaimable. Reaching the flaw requires root access to /dev/liveupdate, equivalent to CAP_SYS_ADMIN, and reclaiming the affected folio discards its user data.
Summary
What happened
Data loss in Linux Kernel 6.19 allows local users to discard memfd contents during a live update under memory pressure. The memfd_luo preservation path serializes a folio's dirty state at preserve time even though mapped pages can become dirty later, so retrieval can restore user data as clean and reclaimable. Reaching the flaw requires root access to /dev/liveupdate, equivalent to CAP_SYS_ADMIN, and reclaiming the affected folio discards its user data.
The record
- CVE
- CVE-2026-43389
- Published
- May 8, 2026
- Updated
- May 8, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux Kernel
- Classifications
- T1485
- Attack vector
- local
- Privileges
- admin
Timeline
How it unfolded
- May 8, 2026CVE publishedPublication date reported by the CVE source.
- May 8, 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=6.19
- Affected versionversion=b3749f174d686627f702234e64bad976dc432dbc <7e04bf1f33151a30e06a65b74b5f2c19fc2be128
- Affected versionversion=b3749f174d686627f702234e64bad976dc432dbc <e901c871d4b592f0042e30f3a0f031eae79744ec
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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