CVE-2026-104855: low-severity vulnerability in bytecodealliance wasmtime
Wasmtime: Preemption and traps during bulk operations enable breaking internal VM state
Published · Updated
8Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 2epss 0.3%
exploitation probability
0.3%top 82% of all CVEs
observed exploitation
nono source reports it
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.
CVSS:4.0/AV:N/AC:H/AT:P/PR:H/UI:P/VC:N/VI:L/VA:L/SC:N/SI:N/SA:N
Affected products
bytecodealliance · wasmtimeRelated CVEs — bytecodealliance wasmtime
In the same product, most dangerous first.
CVE-2022-31104MEDIUMMiscompilation of `i8x16.swizzle` and `select` with v128 inputs in WasmtimeEPSS 1.8%CVE-2023-26489CRITICALGuest-controlled out-of-bounds read/write on x86_64 in wasmtimeEPSS 1.3%CVE-2022-31146MEDIUMUse After Free in WasmtimeEPSS 1.3%CVE-2022-24791HIGHUse after free in WasmtimeEPSS 1.2%CVE-2022-31169MEDIUMCranelift vulnerable to miscompilation of constant values in division on AArch64EPSS 0.9%CVE-2024-51745LOWWasmtime doesn't fully sandbox all the Windows device filenamesEPSS 0.8%
References
https://github.com/bytecodealliance/wasmtime/commit/3ebfbe5af4927c157d6fcaca42b8dbb6d17b73fbhttps://github.com/bytecodealliance/wasmtime/commit/99b0bc39d447317a4102c056081c83a9a84a46e0https://github.com/bytecodealliance/wasmtime/commit/a3eb27af01ba5a30320a90ea1405059cdfedd353https://github.com/bytecodealliance/wasmtime/pull/14041https://github.com/bytecodealliance/wasmtime/pull/14043https://github.com/bytecodealliance/wasmtime/pull/14045https://github.com/bytecodealliance/wasmtime/releases/tag/v46.0.2https://github.com/bytecodealliance/wasmtime/releases/tag/v47.0.3https://github.com/bytecodealliance/wasmtime/security/advisories/GHSA-2hw9-mc66-jc2q