CVE-2025-58749: Bytecodealliance Webassembly Micro Runtime

Medium severity, CVSS 5.3. EPSS: 0.4% chance of exploitation in the next 30 days.

WebAssembly Micro Runtime (WAMR) is a lightweight standalone WebAssembly (Wasm) runtime. In WAMR versions prior to 2.4.2, when running in LLVM-JIT mode, the runtime cannot exit normally when executing WebAssembly programs containing a memory.fill instruction where the first operand (memory address pointer) is greater than or equal to 2147483648 bytes (2GiB). This causes the runtime to hang in release builds or crash in debug builds due to accessing an invalid pointer. The issue does not occur in FAST-JIT mode or other runtime tools. This has been fixed in version 2.4.2.

Affected products

• Bytecodealliance Webassembly Micro Runtime: before 2.4.2 (fixed in 2.4.2)

Published 2025-09-16. Last modified 2026-06-17.