CVE-2026-119141

Wasmtime 46.0.0 before 48.0.6 and 49.0.0 before 49.0.3 Host Panic via realloc

State: Published
Severity: 6.9 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 Wasm modules to panic the host because the may_leave flag is not cleared during realloc. Attackers can call into the host from realloc while lowering stream or future results, such as cancelling the active read or re-waiting a waitable-set, crashing the host.

Scores

CVSS	Score	Vector	Source
4.0	6.9 Medium	CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N	VulnCheck
3.1	5.3 Medium	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L	VulnCheck

Weaknesses

CWE-1265 Unintended Reentrant Invocation of Non-reentrant Code Via Nested Calls

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-7v24-42x9-pxf7)vendor-advisory
VulnCheck Advisory: Wasmtime 46.0.0 before 48.0.6 and 49.0.0 before 49.0.3 Host Panic via reallocthird-party-advisory

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