Description
Wasmtime before 36.0.16, 37.0.0 before 48.0.3, and 49.0.0 before 49.0.1 does not adequately account for host allocations when lifting guest values through the dynamically-typed Val API, bypassing the hostcall fuel limit. A malicious WebAssembly guest can return crafted values that allocate at least ~100x more host memory than tracked, causing denial of service.
Published: 2026-10-22
Score: 1 Low
EPSS: n/a
KEV: No
Impact: n/a
Action: n/a
AI Analysis

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Remediation

No vendor fix or workaround currently provided.

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Tracking

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Advisories

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History

Fri, 23 Oct 2026 00:45:00 +0000

Type Values Removed Values Added
Description Wasmtime before 36.0.16, 37.0.0 before 48.0.3, and 49.0.0 before 49.0.1 does not adequately account for host allocations when lifting guest values through the dynamically-typed Val API, bypassing the hostcall fuel limit. A malicious WebAssembly guest can return crafted values that allocate at least ~100x more host memory than tracked, causing denial of service.
Title Wasmtime before 36.0.16, 37.0.0 before 48.0.3, and 49.0.0 before 49.0.1 Denial of Service via Val API
First Time appeared Bytecodealliance
Bytecodealliance wasmtime
Weaknesses CWE-770
CPEs cpe:2.3:a:bytecodealliance:wasmtime:*:*:*:*:*:*:*:*
Vendors & Products Bytecodealliance
Bytecodealliance wasmtime
References
Metrics cvssV3_1

{'score': 2.3, 'vector': 'CVSS:3.1/AV:A/AC:H/PR:L/UI:R/S:U/C:N/I:N/A:L'}

cvssV4_0

{'score': 1, 'vector': 'CVSS:4.0/AV:A/AC:H/AT:P/PR:L/UI:P/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N'}


Subscriptions

Bytecodealliance Wasmtime
cve-icon MITRE

Status: PUBLISHED

Assigner: VulnCheck

Published:

Updated: 2026-10-22T19:13:55.163Z

Reserved: 2026-10-22T11:27:18.001Z

Link: CVE-2026-115389

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Deferred

Published: 2026-10-22T19:17:46.330

Modified: 2026-10-22T19:17:46.453

Link: CVE-2026-115389

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-10-23T03:30:15Z

Weaknesses
  • CWE-770

    Allocation of Resources Without Limits or Throttling