Component Functionality Flaw in Wasmtime by Bytecode Alliance
CVE-2026-119139

5.9MEDIUM

Key Information:

Vendor

Bytecodealliance

Status
Wasmtime
Vendor
CVE Published:
29 October 2026

What is CVE-2026-119139?

A flaw in Wasmtime versions 46.0.0 through 49.0.2 allows an attacker to exploit guest exports utilizing the async ABI option. By submitting a component with an async-lifted export, a malicious actor can trigger a crash in the host process. This occurs during the invocation of the export via Func::call, resulting in potential service disruptions and compromised stability for applications relying on these versions.

Affected Version(s)

wasmtime 46.0.0 < 48.0.6

wasmtime 49.0.0 < 49.0.3

wasmtime 48.0.6

References

https://github.com/bytecodealliance/wasmtime/security/adv...
vendor-advisory
https://www.vulncheck.com/advisories/wasmtime-46.0.0-befo...
third-party-advisory

CVSS V4

Score:
5.9
Severity:
MEDIUM
Confidentiality:
None
Integrity:
None
Availability:
High
Attack Vector:
Network
Attack Complexity:
High
Attack Required:
Physical
Privileges Required:
Undefined
User Interaction:
Unknown

Timeline

  • Vulnerability published

  • Vulnerability Reserved

Credit

tschneidereit
.