CVE-2026-54914 json
WebAssembly Micro Runtime: Heap Buffer Overflow in WAMR WASI poll_oneoff Output Buffer
published 2026-11-05 3 d ago modified 2026-11-05 3 d ago also EUVD-2026-117615
- cvss
- 8.3
- version 4.0, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.4%
- EPSS 0.4% chance of exploitation in 30 days, percentile 34%
- public exploits
- 0
- none known
Summary
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.
Patch / fix
Exploit prediction
0.40% chance of exploitation in the next 30 days, higher than 34% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 4.0 | 8.3 | 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 | 4.0 | 8.3 | 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/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 |
Affected products
- bytecodealliance wasm-micro-runtime
Classification
- Weakness
-
- CWE-122 Heap-based Buffer Overflow
References
- github.com /wasm-micro-runtime/wasm-micro-runtime/commit/1f98fb01d09b2ef5e49dc0be2e6006f962fd87f1
- github.com /wasm-micro-runtime/wasm-micro-runtime/commit/b49d10eac4176817305d60ea59d24bc69a53eb7b
- github.com /wasm-micro-runtime/wasm-micro-runtime/security/advisories/GHSA-wj3p-xhqm-pffc
- github.com /wasm-micro-runtime/wasm-micro-runtime/releases/tag/WAMR-2.4.5
Sources
- CVE List CVE-2026-54914
- NVD CVE-2026-54914
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