{"id":"CVE-2026-54912","aliases":["EUVD-2026-117617","GHSA-jjv3-x3jf-cg49"],"status":"published","title":"WAMR fast interpreter loader heap buffer overflow via constant deduplication mismatch","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.","severity":{"version":"4.0","score":8.8,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:H/VA:H/SC:N/SI:N/SA:N","level":"high","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-10","score":0.00451,"percentile":0.39499,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-787"],"published":"2026-11-05T17:29:18Z","modified":"2026-11-05T21:32:25Z","products":[{"vendor":"bytecodealliance","product":"wasm-micro-runtime"}],"references":[{"url":"https://github.com/wasm-micro-runtime/wasm-micro-runtime/security/advisories/GHSA-jjv3-x3jf-cg49","tags":["x_refsource_CONFIRM","exploit","advisory"]},{"url":"https://github.com/wasm-micro-runtime/wasm-micro-runtime/commit/b1353b5e8983047ff68829c99abf1355d5f389cf","tags":["x_refsource_MISC","fix"]},{"url":"https://gist.github.com/shumbo/b710c35b005ed871447fce385d1ab760","tags":["x_refsource_MISC","web"]},{"url":"https://github.com/wasm-micro-runtime/wasm-micro-runtime/releases/tag/WAMR-2.4.5","tags":["x_refsource_MISC","web"]},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/54xxx/CVE-2026-54912.json","tags":["advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-54912","tags":["advisory"]}],"sources":{"cve":[{"id":"CVE-2026-54912","title":"WAMR fast interpreter loader heap buffer overflow via constant deduplication mismatch","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.","status":"published","published":"2026-11-05T17:29:18.708Z","modified":"2026-11-05T18:44:51.857Z","cvss":[{"version":"4.0","score":8.8,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:H/VA:H/SC:N/SI:N/SA:N","level":"high","assessor":"cna"}],"cwes":["CWE-787"],"updated_at":"2026-11-05T19:54:51.398642Z"}],"euvd":[{"id":"EUVD-2026-117617","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.","status":"published","published":"2026-11-05T17:29:18Z","modified":"2026-11-05T18:44:51Z","cvss":[{"version":"4.0","score":8.8,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:H/VA:H/SC:N/SI:N/SA:N","level":"high"}],"updated_at":"2026-11-05T20:01:48.85376Z"}],"nvd":[{"id":"CVE-2026-54912","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.","status":"published","published":"2026-11-05T18:17:08.523Z","modified":"2026-11-05T19:17:21.52Z","cvss":[{"version":"4.0","score":8.8,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","level":"high","assessor":"secondary"}],"cwes":["CWE-787"],"updated_at":"2026-11-05T21:56:50.099578Z"}],"osv":[{"id":"CVE-2026-54912","title":"WAMR fast interpreter loader heap buffer overflow via constant deduplication mismatch","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.","status":"published","published":"2026-11-05T17:29:18.708Z","modified":"2026-11-07T07:06:34.330875199Z","cvss":[{"version":"4.0","score":8.8,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:H/VA:H/SC:N/SI:N/SA:N","level":"high"}],"cwes":["CWE-787"],"updated_at":"2026-11-07T03:08:07.380133Z"}]}}