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Response snapshot Nov 5, 2026, 23:11 UTC

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VulnerabilityCVE-2026-54914

WebAssembly Micro Runtime (WAMR) is a lightweight standalone WebAssembly (Wasm) runtime.

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.

At a glance

Exploited
Not known
Severity
8.3 High (CVSS 4.0)
Chance of exploitation
Not estimated
Sources
1 source

What to do

Check the vendor advisory for affected versions and fixes.

Read NVD CVE-2026-54914 (opens a new tab)

What happened

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.

Scores and how they were measured

CVSS base severity

8.3

Version 4.0As of

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

Measurement source (opens a new tab)

How bad it is if exploited. Not a prediction of exploitation or proof you are exposed.

EPSS probability

Not available

A model's estimate of exploitation in the next 30 days, not certainty or your own risk.

Sources

  1. Primary source

    NVD CVE-2026-54914 (opens a new tab)

    NVD record: description, CVSS (the CNA score is preferred), affected products, and publication date. Not evidence of exploitation.

    Published Checked

  2. Primary source

    NVD CVE API 2.0 (opens a new tab)

    The NVD API page that supplied this CVE record.

    Published Date not suppliedChecked

  3. Primary source

    NVD CVE API 2.0 (opens a new tab)

    The NVD API page that supplied this CVE record.

    Published Date not suppliedChecked

  4. Primary source

    NVD CVE API 2.0 (opens a new tab)

    The NVD API page that supplied this CVE record.

    Published Date not suppliedChecked

Cite this record

For factual claims, cite the primary sources above; cite KEVWire for its compilation, dates, and classifications.

APA

KEVWire. (2026, November 5). WebAssembly Micro Runtime (WAMR) is a lightweight standalone WebAssembly (Wasm) runtime. (CVE-2026-54914). https://kevwire.com/record/CVE-2026-54914

MLA

"WebAssembly Micro Runtime (WAMR) is a lightweight standalone WebAssembly (Wasm) runtime. (CVE-2026-54914)." KEVWire, 5 Nov. 2026, kevwire.com/record/CVE-2026-54914.

Chicago

KEVWire. "WebAssembly Micro Runtime (WAMR) is a lightweight standalone WebAssembly (Wasm) runtime. (CVE-2026-54914)." Last modified November 5, 2026. https://kevwire.com/record/CVE-2026-54914.

Evidence summary (plain text)

WebAssembly Micro Runtime (WAMR) is a lightweight standalone WebAssembly (Wasm) runtime. (Nov 5, 2026).
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.
CVSS 8.3 (version 4.0; evidence as of Nov 5, 2026; https://nvd.nist.gov/vuln/detail/CVE-2026-54914).
Sources:
NVD CVE-2026-54914: https://nvd.nist.gov/vuln/detail/CVE-2026-54914
NVD CVE API 2.0: https://services.nvd.nist.gov/rest/json/cves/2.0?lastModStartDate=2026-11-05T18:10:58.021Z&lastModEndDate=2026-11-05T19:40:56.014Z&resultsPerPage=500&startIndex=0
NVD CVE API 2.0: https://services.nvd.nist.gov/rest/json/cves/2.0?lastModStartDate=2026-11-05T17:41:02.410Z&lastModEndDate=2026-11-05T19:10:56.278Z&resultsPerPage=500&startIndex=0
NVD CVE API 2.0: https://services.nvd.nist.gov/rest/json/cves/2.0?lastModStartDate=2026-11-05T17:06:18.295Z&lastModEndDate=2026-11-05T18:40:58.469Z&resultsPerPage=500&startIndex=0
Record ID: CVE-2026-54914.
Record origin: Ingested record.
AI evidence: Not assessed.
Known exploitation: Not assessed.
Zero-day status: Not assessed. KEV membership alone does not establish zero-day status.
About this data

This record was ingested from a data source. Retrieved: Nov 5, 2026, 19:40 UTC. Ingestion is not an independent editorial investigation.

NVD status: Received. Publication in the NVD is not evidence of exploitation.

A CISA KEV listing documents known exploitation, not necessarily a zero-day; absence from the catalog does not prove a vulnerability has never been exploited.

Technology tags indicate possible relevance, not verified exposure. Confirm the affected product, version, and configuration against your own inventory; KEVWire does not scan your systems.

A personal reading checklist on this device, not verified remediation.

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Record details

Record detail