Bytecodealliance vulnerabilities
We track 31 vulnerabilities in Bytecodealliance products across 4 products. 31 are rated high or critical, and none are known to be exploited. The most recent was published on November 5, 2026.
Latest Bytecodealliance vulnerabilities
- 8.3 High severity
wasm-micro-runtime: Heap-based Buffer Overflow
WebAssembly Micro Runtime (WAMR) is a lightweight standalone WebAssembly (Wasm) runtime. Prior to 2.4.5, wasi_poll_oneoff in core/iwasm/libraries/libc-wasi/libc_wasi_wrapper.c validates the output pointer for only one wasi_event_t, while wasmtime_ssp_poll_oneo
- 8.8 High severity
wasm-micro-runtime: Out-of-bounds Write
WebAssembly Micro Runtime (WAMR) is a lightweight standalone WebAssembly (Wasm) runtime. Prior to 2.4.5, the two-pass fast interpreter loader in core/iwasm/interpreter/wasm_loader.c can make inconsistent constant-table decisions between the sizing pass and the
- 7.9 High severity
wasmtime: UNIX Symbolic Link (Symlink) Following
wasmtime-wasi in Wasmtime before 36.0.18, 37.0.0 before 48.0.6, and 49.0.0 before 49.0.3 re-appends a trailing slash to rename source paths, causing renameat on macOS and FreeBSD hosts to follow directory symlinks. A guest with sandbox write access can rename
- 9.9 Critical severity
wasmtime: Insufficient Control Flow Management
Wasmtime is a runtime for WebAssembly. Prior to 36.0.19, 48.0.7, and 49.0.4, the Cranelift compiler backend on aarch64 can compile a Wasm br_table instruction with more than approximately 256,000 targets so that it has an incorrect conditional branch target. T
- 9.9 Critical severity
wasmtime: Numeric Truncation Error
Wasmtime is a runtime for WebAssembly. Prior to 36.0.19 and 43.0.0, the Cranelift compiler backend bit-packs SSA value indices in a way that can silently overflow in release builds when compiling a sufficiently large or specially crafted Wasm function with man
- 7.9 High severity
wasmtime: UNIX Symbolic Link (Symlink) Following
Wasmtime before 24.0.13, 25.0.0 before 36.0.14, 37.0.0 before 46.0.3, and 47.0.0 before 47.0.4 allows a filesystem sandbox escape in wasmtime-wasi because its cap-std dependency mishandles symlinks with trailing slashes on macOS and Linux kernels lacking opena
- 9.9 Critical severity
Wasmtime 39.0.0 before 48.0.4 and 49.0.0 before 49.0.2 contains a stack buffer overflow…
Wasmtime 39.0.0 before 48.0.4 and 49.0.0 before 49.0.2 contains a stack buffer overflow vulnerability that allows malicious guests to write ~16KB to the native stack via unvalidated async callback result types. Attackers can supply components with mistyped com
- 7.5 High severity
wasmtime: Improper Access Control
Wasmtime is a runtime for WebAssembly. In versions prior to 24.0.9, 36.0.10, and 44.0.2, when a filesystem preopen is given DirPerms::all() and FilePerms::READ without FilePerms::WRITE, this access control mechanism can be bypassed via the wasip2 descriptor.op
- 7.5 High severity
wasmtime: Allocation of Resources Without Limits or Throttling
Wasmtime is a runtime for WebAssembly. From 30.0.0 to 36.0.8, 43.0.2, and 44.0.1, Wasmtime's allocation logic for a WebAssembly table contained checked arithmetic which panicked on overflow. This overflow is possible to trigger, and thus panic, when a table wi
- 9.9 Critical severity
wasmtime: Out-of-bounds Read
Wasmtime is a runtime for WebAssembly. From 25.0.0 to before 36.0.7, 42.0.2, and 43.0.1, Wasmtime with its Winch (baseline) non-default compiler backend may allow properly constructed guest Wasm to access host memory outside of its linear-memory sandbox. This
- 8.5 High severity
wasmtime: Out-of-bounds Read
Wasmtime is a runtime for WebAssembly. From 32.0.0 to before 36.0.7, 42.0.2, and 43.0.1, Wasmtime's Cranelift compilation backend contains a bug on aarch64 when performing a certain shape of heap accesses which means that the wrong address is accessed. When co
- 7.5 High severity
wasmtime: Always-Incorrect Control Flow Implementation
Wasmtime is a runtime for WebAssembly. From 25.0.0 to before 36.0.7, 42.0.2, and 43.0.1, Wasmtime's Winch compiler contains a vulnerability where the compilation of the table.fill instruction can result in a host panic. This means that a valid guest can be com
- 7.5 High severity
wasmtime: Uncaught Exception
Wasmtime is a runtime for WebAssembly. Prior to 24.0.7, 36.0.7, 42.0.2, and 43.0.1, Wasmtime contains a possible panic which can happen when a flags-typed component model value is lifted with the Val type. If bits are set outside of the set of flags the compon
- 8.1 High severity
wasmtime: Out-of-bounds Read
Wasmtime is a runtime for WebAssembly. Prior to 24.0.7, 36.0.7, 42.0.2, and 43.0.1, Wasmtime contains a vulnerability where when transcoding a UTF-16 string to the latin1+utf16 component-model encoding it would incorrectly validate the byte length of the input
- 7.5 High severity
wasmtime: Allocation of Resources Without Limits or Throttling
Wasmtime is a runtime for WebAssembly. Prior to versions 24.0.6, 36.0.6, 4.0.04, 41.0.4, and 42.0.0, Wasmtime's implementation of the `wasi:http/types.fields` resource is susceptible to panics when too many fields are added to the set of headers. Wasmtime's im
- 7.5 High severity
wasmtime: Improper Handling of Exceptional Conditions
Wasmtime is a runtime for WebAssembly. Starting with Wasmtime 39.0.0, the `component-model-async` feature became the default, which brought with it a new implementation of `[Typed]Func::call_async` which made it capable of calling async-typed guest export func
- 7.4 High severity
wasm-micro-runtime: Improper Restriction of Operations within the Bounds of a Memory Buffer
WebAssembly Micro Runtime (WAMR) is a lightweight standalone WebAssembly (Wasm) runtime. Prior to version 2.4.4, an out-of-bounds array access issue exists in WAMR's fast interpreter mode during WASM bytecode loading. When frame_ref_bottom and frame_offset_bot
- 7.5 High severity
webassembly_micro_runtime: NULL Pointer Dereference
wasm-micro-runtime (aka WebAssembly Micro Runtime or WAMR) 06df58f is vulnerable to NULL Pointer Dereference in function `block_type_get_result_types.
- 7.8 High severity
webassembly_micro_runtime: Out-of-bounds Read
An issue in bytecodealliance wasm-micro-runtime before v.b3f728c and fixed in commit 06df58f allows a remote attacker to escalate privileges via a crafted file to the check_was_abi_compatibility function.
- 10.0 Critical severity
wasmtime: Improper Handling of Windows Device Names
Wasmtime is a fast and secure runtime for WebAssembly. Wasmtime's filesystem sandbox implementation on Windows blocks access to special device filenames such as "COM1", "COM2", "LPT0", "LPT1", and so on, however it did not block access to the special device fi
- 7.5 High severity
wasm_micro_runtime: Out-of-bounds Read
An out-of-bound memory read vulnerability was discovered in Bytecode Alliance wasm-micro-runtime v2.0.0 which allows a remote attacker to cause a denial of service via the "block_type_get_arity" function in core/iwasm/interpreter/wasm.h.
- 7.5 High severity
Webassembly Micro Runtime: Out-of-bounds Write
An heap overflow vulnerability was discovered in Bytecode alliance wasm-micro-runtime v.1.2.3 allows a remote attacker to cause a denial of service via the wasm_loader_prepare_bytecode function in core/iwasm/interpreter/wasm_loader.c.
- 8.8 High severity
wasmtime: Reliance on Undefined, Unspecified, or Implementation-Defined Behavior
Wasmtime is a standalone runtime for WebAssembly. Prior to versions 6.0.2, 7.0.1, and 8.0.1, Wasmtime's implementation of managing per-instance state, such as tables and memories, contains LLVM-level undefined behavior. This undefined behavior was found to cau
- 9.9 Critical severity
wasmtime: Out-of-bounds Read
wasmtime is a fast and secure runtime for WebAssembly. In affected versions wasmtime's code generator, Cranelift, has a bug on x86_64 targets where address-mode computation mistakenly would calculate a 35-bit effective address instead of WebAssembly's defined
- 9.8 Critical severity
wasmtime: Out-of-bounds Write
Wasmtime is a standalone runtime for WebAssembly. Prior to version 2.0.2, there is a bug in Wasmtime's C API implementation where the definition of the `wasmtime_trap_code` does not match its declared signature in the `wasmtime/trap.h` header file. This discre
- 8.6 High severity
wasmtime: Improper Removal of Sensitive Information Before Storage or Transfer
Wasmtime is a standalone runtime for WebAssembly. Prior to versions 2.0.2 and 1.0.2, there is a bug in Wasmtime's implementation of its pooling instance allocator where when a linear memory is reused for another instance the initial heap snapshot of the prior
- 7.4 High severity
wasmtime: Out-of-bounds Read
Wasmtime is a standalone runtime for WebAssembly. Prior to version 2.0.2, there is a bug in Wasmtime's implementation of its pooling instance allocator when the allocator is configured to give WebAssembly instances a maximum of zero pages of memory. In this co
- 7.5 High severity
wasmtime: Incorrect Calculation
Wasmtime is a standalone runtime for WebAssembly. There is a bug in Wasmtime's code generator, Cranelift, for AArch64 targets where constant divisors can result in incorrect division results at runtime. This affects Wasmtime prior to version 0.38.2 and Craneli
- 8.8 High severity
wasmtime: Use After Free
Wasmtime is a standalone runtime for WebAssembly. There is a bug in the Wasmtime's code generator, Cranelift, where functions using reference types may be incorrectly missing metadata required for runtime garbage collection. This means that if a GC happens at
- 9.8 Critical severity
wasmtime: Use After Free
Wasmtime is a standalone JIT-style runtime for WebAssembly, using Cranelift. There is a use after free vulnerability in Wasmtime when both running Wasm that uses externrefs and enabling epoch interruption in Wasmtime. If you are not explicitly enabling epoch i
- 8.1 High severity
wasmtime: Access of Uninitialized Pointer
Wasmtime is an open source runtime for WebAssembly & WASI. Prior to versions 0.34.1 and 0.33.1, there exists a bug in the pooling instance allocator in Wasmtime's runtime where a failure to instantiate an instance for a module that defines an `externref` globa