Denial of Service Vulnerability in Wasmtime by Bytecode Alliance
CVE-2026-119142

5.9MEDIUM

Key Information:

Vendor

Bytecodealliance

Status
Wasmtime
Vendor
CVE Published:
29 October 2026

What is CVE-2026-119142?

In versions of Wasmtime prior to 48.0.6 and 49.0.3, a denial of service vulnerability exists that can result in the host crashing. This issue stems from the improper handling of a Future returned by TypedFunc::call_async, particularly when the guest task has not started. The cleanup process only checks a single location for work items, leading to a potential panic if an error occurs during the process. This can leave embedders vulnerable when they attempt to cancel pending calls.

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

.