CVE-2026-119140

Wasmtime 46.0.0 before 48.0.6 and 49.0.0 before 49.0.3 Host Panic via thread.yield

State: Published
Severity: 5.9 Medium
Published: Oct 29, 2026
Updated: Oct 29, 2026
Reserved: Oct 29, 2026

Description

Wasmtime 46.0.0 before 48.0.6 and 49.0.0 before 49.0.3 contains a denial of service vulnerability that allows malicious components to panic the host via thread.yield in start functions. Attackers can supply a component whose start function calls an async-lowered import then thread.yield, causing an undisposed fiber drop that crashes embedders.

Scores

CVSS	Score	Vector	Source
4.0	5.9 Medium	CVSS:4.0/AV:N/AC:H/AT:P/PR:L/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N	VulnCheck
3.1	4.8 Medium	CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:U/C:N/I:N/A:H	VulnCheck

Weaknesses

CWE-372 Incomplete Internal State Distinction

Affected Products

Product	Versions
wasmtimebytecodealliance	46.0.0 to before 48.0.6Affected 48.0.6Not affected 49.0.0 to before 49.0.3Affected 49.0.3Not affected

References

GitHub Security Advisory (GHSA-5hhx-4wrr-3j9g)vendor-advisory
VulnCheck Advisory: Wasmtime 46.0.0 before 48.0.6 and 49.0.0 before 49.0.3 Host Panic via thread.yieldthird-party-advisory

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