Wasmtime 46.0.0 before 46.0.3 and 47.0.0 before 47.0.4 Unbounded Heap Allocation via WASIp3 Streams

MITRE NVD CVE.ORG JSON API

Summary

CVECVE-2026-115391
StatePUBLISHED
AssignerVulnCheck
Source PriorityCVE Program / NVD first with legacy fallback
Published2026-10-22 19:17:46 UTC
Updated2026-10-22 19:17:46 UTC
DescriptionWasmtime 46.0.0 before 46.0.3 and 47.0.0 before 47.0.4 contains an uncontrolled resource allocation vulnerability in its WASIp3 implementation that buffers guest-specified-length writes on the host without limit. Malicious guests can offer large buffers to WASIp3 file or HTTP write streams, causing the host to copy and buffer all bytes, bounded only by guest linear memory, exhausting host memory.

Risk And Classification

Primary CVSS: v4.0 6.9 MEDIUM from [email protected]

CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:H/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

Problem Types: CWE-770 | CWE-770 Allocation of Resources Without Limits or Throttling

VersionSourceTypeScoreSeverityVector
4.0[email protected]Secondary6.9MEDIUMCVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:H/E:X/C...
4.0CNACVSS6.9MEDIUMCVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:H
3.1[email protected]Primary5.8MEDIUMCVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:C/C:N/I:N/A:H
3.1CNACVSS5.8MEDIUMCVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:C/C:N/I:N/A:H

CVSS v4.0 Breakdown

Attack Vector
Network
Attack Complexity
Low
Attack Requirements
Present
Privileges Required
Low
User Interaction
Passive
Confidentiality
None
Integrity
None
Availability
High
Sub Conf.
None
Sub Integrity
None
Sub Availability
High

CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:H/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

CVSS v3.1 Breakdown

Attack Vector
Network
Attack Complexity
High
Privileges Required
Low
User Interaction
Required
Scope
Changed
Confidentiality
None
Integrity
None
Availability
High

CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:C/C:N/I:N/A:H

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA Bytecodealliance Wasmtime affected 46.0.0 46.0.3 semver Not specified
CNA Bytecodealliance Wasmtime unaffected 46.0.3 semver Not specified
CNA Bytecodealliance Wasmtime affected 47.0.0 47.0.4 semver Not specified
CNA Bytecodealliance Wasmtime unaffected 47.0.4 semver Not specified

References

ReferenceSourceLinkTags
www.vulncheck.com/advisories/wasmtime-46.0.0-before-46.0.3-and-47.0.0-before-47... [email protected] www.vulncheck.com
github.com/bytecodealliance/wasmtime/security/advisories/GHSA-x84v-gj2h-... [email protected] github.com
CVE Program record CVE.ORG www.cve.org canonical
NVD vulnerability detail NVD nvd.nist.gov canonical, analysis

Vendor Comments And Credit

Discovery Credit

CNA: tschneidereit (en)

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