CVE-2026-54914
WebAssembly Micro Runtime: Heap Buffer Overflow in WAMR WASI poll_oneoff Output Buffer
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_oneoff in core/iwasm/libraries/libc-wasi/sandboxed-system-primitives/src/posix.c can write as many events as the guest-controlled nsubscriptions value. A crafted guest module can provide multiple subscriptions that produce events while positioning an output region large enough for only one event, causing a later out[nevents] write to cross the validated Wasm linear-memory boundary into adjacent host heap memory. The overwrite contains partly attacker-controlled event data and can reliably crash the host process, with further confidentiality or integrity consequences depending on heap layout. This issue is fixed in version 2.4.5.
Fixes and workarounds
No remediation reported in collected sources.
Missing remediation information is not evidence that no patch exists.
Affected products and versions
| Product | Versions | Authority |
|---|---|---|
| wasm-micro-runtime bytecodealliance |
< 2.4.5 (affected) | CNA: GitHub_M |
Version ranges are source assertions. Check the vendor advisory and your installed configuration before determining exposure.
CVSS assessments
| Version / score | Vector | Authority |
|---|---|---|
| 4.0 / 8.3 high |
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:L/VA:H/SC:N/SI:N/SA:N | CNA: GitHub_M |
Exploit evidence
No exploit evidence in collected sources. This is not proof of no exploitation.
References
- https://github.com/wasm-micro-runtime/wasm-micro-runtime/security/advisories/GHSA-wj3p-xhqm-pffcCNA: GitHub_M · x_refsource_CONFIRM
- https://github.com/wasm-micro-runtime/wasm-micro-runtime/commit/1f98fb01d09b2ef5e49dc0be2e6006f962fd87f1CNA: GitHub_M · x_refsource_MISC
- https://github.com/wasm-micro-runtime/wasm-micro-runtime/commit/b49d10eac4176817305d60ea59d24bc69a53eb7bCNA: GitHub_M · x_refsource_MISC
- https://github.com/wasm-micro-runtime/wasm-micro-runtime/releases/tag/WAMR-2.4.5CNA: GitHub_M · x_refsource_MISC
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