---
id: CVE-2026-27572
aliases:
  - RUSTSEC-2026-0021
  - GHSA-243v-98vx-264h
title: 'Panic adding excessive fields to a `wasi:http/types.fields` instance'
summary: 'Panic adding excessive fields to a `wasi:http/types.fields` instance'
severity: none
vendor: wasmtime
product: wasmtime
ecosystem: rust
affected:
  - 'wasmtime >= 41.0.0, < 41.0.4'
patched:
  - wasmtime 41.0.4
published: '2026-02-24'
updated: '2026-10-12'
sourceUpdated: '2026-10-12T18:00:13.556608408Z'
source: OSV
sourceUrl: 'https://osv.dev/vulnerability/RUSTSEC-2026-0021'
references:
  - url: 'https://crates.io/crates/wasmtime'
  - url: 'https://rustsec.org/advisories/RUSTSEC-2026-0021.html'
  - url: >-
      https://github.com/bytecodealliance/wasmtime/commit/301dc7162cca51def19131019af1187f45901c0a
tags:
  - osv
  - rust
epss: 0.00663
epssPercentile: 0.50319
ingestedAt: '2026-10-13T11:45:30.184Z'
---

## Overview

This is an entry in the RustSec database for the Wasmtime security advisory
located at
https://github.com/bytecodealliance/wasmtime/security/advisories/GHSA-243v-98vx-264h
For more information see the GitHub-hosted security advisory.

## Affected packages

- `wasmtime >= 41.0.0, < 41.0.4`

## Remediation

Upgrade to a patched release:

- `wasmtime 41.0.4`