# CVE-2026-119136: Wasmtime 42.0.0 before 48.0.6 and 49.0.0 before 49.0.3 Async-Entrypoint Enforcement Bypass


- **Severity:** Medium 5.9 (`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`)
- **Exploited in the wild:** Not known
- **Fix available:** Yes
- **Published:** 29 Oct 2026
- **Updated:** 29 Oct 2026
- **Also known as:** GHSA-vcg5-q8m5-8379, GHSA-xp2q-mv29-hr2p, RUSTSEC-2026-0362

## What is CVE-2026-119136?

CVE-2026-119136 is a medium-severity vulnerability in bytecodealliance wasmtime, published on 29 Oct 2026. 

### Official description

Wasmtime 42.0.0 before 48.0.6 and 49.0.0 before 49.0.3 contains insufficient checks in Store when mixing async-style and sync-style WebAssembly calls. Embedders re-entering WebAssembly via sync APIs from host functions called asynchronously can trigger runtime panics or unsound cross-thread movement of !Send host variables.

Weakness: CWE-1265 (Unintended Reentrant Invocation of Non-reentrant Code Via Nested Calls)

## Which versions are affected by CVE-2026-119136?

1 open source package ship an affected version, including wasmtime.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `wasmtime` | crates.io | From 42.0.0 | 48.0.6, 49.0.3 |

## How do I fix CVE-2026-119136?

Upgrade wasmtime to a fixed version for your release line: 48.0.6 or 49.0.3.

## Is CVE-2026-119136 being exploited?

There is no known exploitation of CVE-2026-119136 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-119136 and fix it if it is affected.

What it is: CVE-2026-119136 is a medium-severity vulnerability in bytecodealliance wasmtime, published on 29 Oct 2026. 
Exploitation: There is no known exploitation of CVE-2026-119136 in the wild and no public exploit code.

Affected packages and fixed versions:
- wasmtime (crates.io): affected from 42.0.0; fixed in 48.0.6, 49.0.3

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-119136/ (Markdown: https://insights.sbomify.com/CVE-2026-119136/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-119136
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-119136
- OSV: https://osv.dev/vulnerability/CVE-2026-119136

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-119136/
Summaries are generated and may contain mistakes; the official description above is the record.