---
id: "CVE-2026-119138"
kind: "vulnerability"
aliases: ["CVE-2026-119138"]
title: "Wasmtime: crafted guest code crashes hosts reusing a poisoned Store"
severity: "medium"
cvss: 5.9
epss: null
exploited: false
status: "open"
category: "runtime"
products: []
ecosystems: []
tags: ["runtime", "rust", "wasmtime", "webassembly"]
not_affected_if: ["no-store-reuse-after-trap", "trusted-guest-code-only"]
published_at: "2026-10-29T16:18:07+00:00"
first_seen_at: "2026-10-29T16:25:58+00:00"
updated_at: "2026-10-29T16:31:39+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-119138", "first_seen_at": "2026-10-29T16:25:58+00:00"}]
---

# Wasmtime: crafted guest code crashes hosts reusing a poisoned Store

Wasmtime versions 46.0.0 before 48.0.6 and 49.0.0 before 49.0.3 let pending calls hit an assertion failure after a trap poisons the Store. Attackers who supply misbehaving guest code can crash embedders that keep using the inconsistent Store, causing denial of service.

_Summary, check and fix written by a model from the sources; labelled as such._

## How to check

- Check the Wasmtime version in your dependencies, for example `wasmtime --version` or the `wasmtime` entry in `Cargo.lock`
- Look for embedders that keep calling into a Store after a trap and run untrusted guest code

## Fix

- Wasmtime `48.0.6` for the 46/48 line
- Wasmtime `49.0.3` for the 49 line

## Timeline

- 2026-10-29T16:25:58+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-119138

## From the sources

Wasmtime 46.0.0 before 48.0.6 and 49.0.0 before 49.0.3 contains a denial of service vulnerability that allows pending calls to trigger an assertion failure after a trap poisons the Store. Attackers supplying misbehaving guest code can cause a trap and let earlier calls proceed, crashing embedders that continue using the inconsistent Store.

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_Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai_