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 emitting pass. After duplicate constants inflate the first pass beyond the constant-slot limit, wasm_loader_get_const_offset emits later constants inline, but the between-pass sort and deduplication reduces the table so the second pass can choose table references and cause reserve_block_ret to emit additional copy operands that were not included in code_compiled_peak_size. A crafted module can therefore make the second pass write partially attacker-controlled compiled-code data beyond the heap buffer allocated from the first pass's size calculation during wasm_runtime_load, before guest code executes. This can corrupt host heap metadata and deterministically crash the process, causing denial of service; further consequences depend on the host application's heap layout. Builds using WAMR_BUILD_FAST_INTERP=1 are affected; disabling the fast interpreter avoids the vulnerable loader. This issue is fixed in version 2.4.5.
Metrics
Affected Vendors & Products
Advisories
No advisories yet.
Fixes
Solution
No solution given by the vendor.
Workaround
No workaround given by the vendor.
References
History
Thu, 05 Nov 2026 17:45:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | 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 emitting pass. After duplicate constants inflate the first pass beyond the constant-slot limit, wasm_loader_get_const_offset emits later constants inline, but the between-pass sort and deduplication reduces the table so the second pass can choose table references and cause reserve_block_ret to emit additional copy operands that were not included in code_compiled_peak_size. A crafted module can therefore make the second pass write partially attacker-controlled compiled-code data beyond the heap buffer allocated from the first pass's size calculation during wasm_runtime_load, before guest code executes. This can corrupt host heap metadata and deterministically crash the process, causing denial of service; further consequences depend on the host application's heap layout. Builds using WAMR_BUILD_FAST_INTERP=1 are affected; disabling the fast interpreter avoids the vulnerable loader. This issue is fixed in version 2.4.5. | |
| Title | WAMR fast interpreter loader heap buffer overflow via constant deduplication mismatch | |
| Weaknesses | CWE-787 | |
| References |
|
|
| Metrics |
cvssV4_0
|
Projects
Sign in to view the affected projects.
Status: PUBLISHED
Assigner: GitHub_M
Published:
Updated: 2026-11-05T18:44:51.857Z
Reserved: 2026-06-16T13:49:33.556Z
Link: CVE-2026-54912
No data.
Status : Received
Published: 2026-11-05T18:17:08.523
Modified: 2026-11-05T19:17:21.520
Link: CVE-2026-54912
No data.
OpenCVE Enrichment
Updated: 2026-11-05T19:30:11Z
Weaknesses