Cryptographic secret compromise via falsely successful RDSEED
Published Dec 16, 2025 · Updated Dec 16, 2025
Insufficient entropy handling in the Linux kernel allows local users to compromise cryptographic secrets via 16-bit or 32-bit RDSEED. The Zen 5 initialization path in arch/x86/kernel/cpu/amd.c fails to check affected microcode revisions or clear RDSEED support, although these forms can return zero while signaling success. An unprivileged local process can drive the concurrent RDSEED and memory-pressure workload; exposure arises when software consumes the falsely successful output as seed material.
Summary
What happened
Insufficient entropy handling in the Linux kernel allows local users to compromise cryptographic secrets via 16-bit or 32-bit RDSEED. The Zen 5 initialization path in arch/x86/kernel/cpu/amd.c fails to check affected microcode revisions or clear RDSEED support, although these forms can return zero while signaling success. An unprivileged local process can drive the concurrent RDSEED and memory-pressure workload; exposure arises when software consumes the falsely successful output as seed material.
The record
- CVE
- CVE-2025-68313
- Published
- Dec 16, 2025
- Updated
- Dec 16, 2025
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- Unavailable
- Attack vector
- local
- Privileges
- Unavailable
Timeline
How it unfolded
- Dec 16, 2025CVE publishedPublication date reported by the CVE source.
- Dec 16, 2025Record 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=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <36ff93e66d0efc46e39fab536a9feec968daa766
- Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <607b9fb2ce248cc5b633c5949e0153838992c152
- Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <e980de2ff109dacb6d9d3a77f01b27c467115ecb
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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Public exploit references
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Technologies
Your stack
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Your stack
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