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CVE-2026-104855RUSTSEC-2026-0223GHSA-2HW9-MC66-JC2Q

Wasmtime: Preemption and traps during bulk operations enable breaking internal VM state

Published
Last modified
published
Not listed in CISA KEV
Fix
Fixed in 46.0.2, 47.0.3
None on Exploit-DB, Metasploit or GitHub
  • Exploitation: none
  • Automatable: no
  • Technical impact: partial

Summary

Wasmtime is a runtime for WebAssembly. From 46.0.0 until 46.0.2 and 47.0.3, fuel and epoch preemption checks inside bulk operations including memory.copy, table.grow, and array.copy can expose invalid intermediate state when an embedder mutates a Store in Store::epoch_deadline_callback or continues using a Store after cancellation or a trap. A cancelled non-nullable table growth can leave null elements, linear-memory growth during memory.copy can invalidate retained raw pointers, and callback-triggered garbage collection during array.copy can invalidate GC pointers, resulting in a crash, invalid memory access, or GC heap corruption. Embeddings whose callbacks only access the host data in Store<T>, and embeddings that discard a Store after timeout or epoch deadline, are not affected. This issue is fixed in versions 46.0.2 and 47.0.3.

Timeline

  1. CVE published
  2. CISA SSVC assessment

    Exploitation: none · Automatable: no · Technical impact: partial

  3. Record last updated

Affected versions

  • bytecodealliance wasmtime

    From 46.0.0 · fixed in 46.0.2; From 47.0.0 · fixed in 47.0.3

  • wasmtimecrates.io

    From 46.0.0 · fixed in 46.0.2

  • wasmtimecrates.io

    From 47.0.0 · fixed in 47.0.3

  • wasmtimecrates.io

    From 46.0.0 · fixed in 46.0.2; From 47.0.0 · fixed in 47.0.3

References 9

GitHub · bytecodealliance/wasmtime