CVE-2026-104855

Public on 2026-10-02
Modified on 2026-10-03
Description
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, 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.
Severity
Medium severity
Medium
See what this means
CVSS v3 Base Score
5.3
See breakdown

Affected Packages

Platform Package Release Date Advisory Status
Amazon Linux 2027 Preview tree-sitter Not Affected

CVSS Scores

Score Type Score Vector
Amazon Linux CVSSv3 5.3 CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:L/A:H