Host data race via unsynchronized shared-memory access
Published Nov 12, 2025 · Updated Nov 12, 2025
Race condition in Bytecode Alliance Wasmtime allows local users to trigger a host data race through shared linear memory. The Memory::new constructor accepts a shared MemoryType and returns Memory accessors as safe byte slices, while core dumps also read shared memory without synchronization. Reachability requires an embedding to use shared memory across threads; the core-dump path also requires off-by-default core dumps, and no disclosure or service interruption is reported.
Summary
What happened
Race condition in Bytecode Alliance Wasmtime allows local users to trigger a host data race through shared linear memory. The Memory::new constructor accepts a shared MemoryType and returns Memory accessors as safe byte slices, while core dumps also read shared memory without synchronization. Reachability requires an embedding to use shared memory across threads; the core-dump path also requires off-by-default core dumps, and no disclosure or service interruption is reported.
The record
- CVE
- CVE-2025-64345
- Published
- Nov 12, 2025
- Updated
- Nov 12, 2025
- Vendor
- Bytecode Alliance
- Product
- Wasmtime
- Classifications
- CWE-362
- Attack vector
- local
- Privileges
- Unavailable
Timeline
How it unfolded
- Nov 12, 2025CVE publishedPublication date reported by the CVE source.
- Nov 12, 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?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=< 24.0.5
- Affected versionversion=>= 26.0.0, < 36.0.3
- Affected versionversion=>= 37.0.0, < 37.0.3
- Affected versionversion=>= 38.0.1, < 38.0.4
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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