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Response snapshot Nov 5, 2026, 23:11 UTC

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VulnerabilityCVE-2026-54912

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, 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.

At a glance

Exploited
Not known
Severity
8.8 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-2026-54912 (opens a new tab)

What happened

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.

Scores and how they were measured

CVSS base severity

8.8

Version 4.0As of

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

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-2026-54912 (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

  5. Primary source

    NVD CVE API 2.0 (opens a new tab)

    The NVD API page that supplied this CVE record.

    Published Date not suppliedChecked

  6. 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-2026-54912). https://kevwire.com/record/CVE-2026-54912

MLA

"WebAssembly Micro Runtime (WAMR) is a lightweight standalone WebAssembly (Wasm) runtime. (CVE-2026-54912)." KEVWire, 5 Nov. 2026, kevwire.com/record/CVE-2026-54912.

Chicago

KEVWire. "WebAssembly Micro Runtime (WAMR) is a lightweight standalone WebAssembly (Wasm) runtime. (CVE-2026-54912)." Last modified November 5, 2026. https://kevwire.com/record/CVE-2026-54912.

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, 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.
CVSS 8.8 (version 4.0; evidence as of Nov 5, 2026; https://nvd.nist.gov/vuln/detail/CVE-2026-54912).
Sources:
NVD CVE-2026-54912: https://nvd.nist.gov/vuln/detail/CVE-2026-54912
NVD CVE API 2.0: https://services.nvd.nist.gov/rest/json/cves/2.0?lastModStartDate=2026-11-05T19:11:00.657Z&lastModEndDate=2026-11-05T20:40:56.332Z&resultsPerPage=500&startIndex=500
NVD CVE API 2.0: https://services.nvd.nist.gov/rest/json/cves/2.0?lastModStartDate=2026-11-05T18:41:04.377Z&lastModEndDate=2026-11-05T20:10:57.103Z&resultsPerPage=500&startIndex=0
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-2026-54912.
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, 20:40 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.

Record JSON

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Record details

Record detail