CVE-2026-54914
WebAssembly Micro Runtime: Heap Buffer Overflow in WAMR WASI poll_oneoff Output Buffer
- Published
- Updated
- Reserved
- Assigned by
- GitHub_M
Description
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.
Timeline
ID reserved
By GitHub_M
- 5 months later
· 5 months later
Published
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| GitHub_MCNA (assigner) | 4.0 | High8.3 | 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 |
| NVDNVD · Received | 4.0 | High8.3 | 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 |
- EPSS (exploitation in 30 days)
- 0.40% · top 66% of all CVEs (7 Nov 2026)
The list uses the assigner's score when there is one, then CISA's, then NVD's: High 8.3.
Weakness
Affected products
bytecodealliance · wasm-micro-runtime
- affected < 2.4.5
References (4)
- https://github.com/wasm-micro-runtime/wasm-micro-runtime/security/advisories/GHSA-wj3p-xhqm-pffc (opens in a new tab)x_refsource_CONFIRM
- https://github.com/wasm-micro-runtime/wasm-micro-runtime/commit/1f98fb01d09b2ef5e49dc0be2e6006f962fd87f1 (opens in a new tab)x_refsource_MISC
- https://github.com/wasm-micro-runtime/wasm-micro-runtime/commit/b49d10eac4176817305d60ea59d24bc69a53eb7b (opens in a new tab)x_refsource_MISC
- https://github.com/wasm-micro-runtime/wasm-micro-runtime/releases/tag/WAMR-2.4.5 (opens in a new tab)x_refsource_MISC
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://trackcve.app/cve/CVE-2026-54914)Record last updated .