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OpenAdvisories
Medium · 4.8 CVE-2026-119143 EUVD-2026-113210GHSA-368p-492j-h227GHSA-93g3-36p8-x2gcRUSTSEC-2026-0357

Wasmtime 46.0.0 before 48.0.6 and 49.0.0 before 49.0.3 Panic via Zero-Length Stream Writes

Published Oct 29, 2026 · Updated Nov 4, 2026 · Assigned by VulnCheck

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 guest code to trigger a host panic through out-of-bounds zero-length stream operations. Malicious guests can perform zero-length component model stream reads or writes with unvalidated addresses, causing Direct{Source,Destination}::remaining to panic and crash WASIp3 embedders.

Affected products

VendorProductAffectedFixed
bytecodealliance wasmtime 46.0.0 – < 48.0.6, 49.0.0 – < 49.0.3 48.0.6

Fixed in Linux distributions

Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.

ReleasePackageFixed inAdvisory
Ubuntu 26.10 rust-wasmtime No fix yet —
Ubuntu 26.04 LTS rust-wasmtime No fix yet —
Ubuntu 24.04 LTS rust-wasmtime No fix yet —

Affected packages

EcosystemPackageAffectedFixedRecord
crates.io wasmtime >= 46.0.0, < 48.0.6 · >= 49.0.0, < 49.0.3 48.0.6, 49.0.3 RUSTSEC-2026-0357

References