What is CVE-2026-119142?

CVE-2026-119142 is a medium-severity vulnerability in Bytecodealliance Wasmtime, classified under Reachable Assertion. CVSS score: 4.8/10. Published 2026-10-29.

How severe is CVE-2026-119142?

Medium severity. CVSS v3 base score is 4.8 out of 10.

Vulnerability in Bytecodealliance Wasmtime

CVE-2026-119142

Wasmtime 46.0.0 before 48.0.6 and 49.0.0 before 49.0.3 contains a denial of service vulnerability where dropping the Future returned by TypedFunc::call_async can panic the host. When the guest task has not started, cleanup code searches only one location for work items and unwraps the resulting error, crashing embedders that cancel pending calls.

Published 2026-10-29 · last modified 2026-10-29.

CVSS v3 metric

CVSS v3 base score 4.8 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:U/C:N/I:N/A:H.

EPSS exploit prediction

No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.

Affected products

Bytecodealliance Wasmtime

Weakness classification (CWE)

CWE-617 — Reachable Assertion

References

github.com/bytecodealliance/wasmtime/security/advisories/GHSA-3r89-v5mq-j5xf (vendor-advisory)
www.vulncheck.com/advisories/wasmtime-46.0.0-before-48.0.6-and-49.0.0-before-49… (third-party-advisory)

Frequently asked questions

What is CVE-2026-119142?: CVE-2026-119142 is a medium-severity vulnerability in Bytecodealliance Wasmtime, classified under Reachable Assertion. CVSS score: 4.8/10. Published 2026-10-29.
How severe is CVE-2026-119142?: Medium severity. CVSS v3 base score is 4.8 out of 10.