critical · 9.4 Patched

Wasmtime component async-lifted callback result count is unvalidated, causing a native stack buffer overflow

CVE-2026-115384 · GHSA-6fff-wrjr-wjxr · EUVD-2026-108311 · GHSA-32h6-97mm-8q3c · RUSTSEC-2026-0327 · published 2 Oct 2026

How serious is it

  • Severity: critical, CVSS score 9.4 out of 10.
  • No exploit prediction (EPSS) score yet.
  • Not on the CISA list of exploited vulnerabilities.
  • No public exploit in Exploit-DB.

Is your app affected by CVE-2026-115384?

Paste this prompt into Claude Code, Cursor or any AI coding tool: it runs a free Shippable scan of your project and fixes what it finds. Built with Lovable, Bolt or v0? Scan your live app. Or upload your package file.

Who is affected

  • wasmtime (crates.io) >= 39.0.0, < 48.0.4
  • wasmtime (crates.io) >= 49.0.0, < 49.0.2

How to check

  1. Run cargo tree -i wasmtime in your project to see the installed version, including copies pulled in by other packages.
  2. Or paste your lockfile into the checker: it lists every package with a known vulnerability, this one included.

How to fix

Copies a prompt for Claude Code, Cursor or Codex: it checks your lockfiles for this and upgrades it.
  1. On >= 39.0.0, < 48.0.4: Upgrade wasmtime to 48.0.4 or later, commit the lockfile and redeploy.
  2. On >= 49.0.0, < 49.0.2: Upgrade wasmtime to 49.0.2 or later, commit the lockfile and redeploy.
  3. If a vulnerable version was live, check your logs and rotate the secrets that server could read.

The advisory

This is an entry in the RustSec database for the Wasmtime security advisory located at https://github.com/bytecodealliance/wasmtime/security/advisories/GHSA-32h6-97mm-8q3c For more information see the GitHub-hosted security advisory.

Check your whole app

Dependencies are only half of it. Free and read-only: before you push, run npx shippable-dev scan localhost:3000 in your project folder, no account needed. For your live app, you prove it's yours with a one-line tag first.

References

Merged from OSV, ENISA EUVD. Last updated 29 Oct 2026. All vulnerabilities · RSS · JSON

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