Wasmtime 47.0.0 before 48.0.6 and 49.0.0 before 49.0.3 Misaligned VMContext via Exception Tags

MITRE NVD CVE.ORG JSON API

Summary

CVECVE-2026-119133
StatePUBLISHED
AssignerVulnCheck
Source PriorityCVE Program / NVD first with legacy fallback
Published2026-10-29 16:18:06 UTC
Updated2026-10-29 18:17:30 UTC
DescriptionWasmtime 47.0.0 before 48.0.6 and 49.0.0 before 49.0.3 contains a memory misalignment flaw in VMContext layout that causes undefined behavior when modules contain an odd number of exception tags. A WebAssembly module with an odd tag count misaligns subsequent host fields in embedders with exceptions enabled, although no exploitation path is currently known.

Risk And Classification

Primary CVSS: v4.0 2.1 LOW from [email protected]

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

Problem Types: CWE-758 | CWE-758 Reliance on Undefined, Unspecified, or Implementation-Defined Behavior

VersionSourceTypeScoreSeverityVector
4.0[email protected]Secondary2.1LOWCVSS:4.0/AV:N/AC:H/AT:P/PR:L/UI:P/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:X/C...
4.0CNACVSS2.1LOWCVSS:4.0/AV:N/AC:H/AT:P/PR:L/UI:P/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N
3.1[email protected]Secondary2.6LOWCVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:U/C:N/I:L/A:N
3.1CNACVSS2.6LOWCVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:U/C:N/I:L/A:N

CVSS v4.0 Breakdown

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

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

CVSS v3.1 Breakdown

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

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

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA Bytecodealliance Wasmtime affected 47.0.0 48.0.6 semver Not specified
CNA Bytecodealliance Wasmtime unaffected 48.0.6 semver Not specified
CNA Bytecodealliance Wasmtime affected 49.0.0 49.0.3 semver Not specified
CNA Bytecodealliance Wasmtime unaffected 49.0.3 semver Not specified

References

ReferenceSourceLinkTags
www.vulncheck.com/advisories/wasmtime-47.0.0-before-48.0.6-and-49.0.0-before-49... [email protected] www.vulncheck.com
github.com/bytecodealliance/wasmtime/security/advisories/GHSA-p79w-pv2r-... [email protected] github.com
CVE Program record CVE.ORG www.cve.org canonical
NVD vulnerability detail NVD nvd.nist.gov canonical, analysis

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