Wasmtime: sandbox escape

Wasmtime

Two critical flaws in Wasmtime could allow a malicious WebAssembly module to escape the sandbox, affecting ARM64 systems.

Do this now

Check the Wasmtime vendor advisory for a fix and restrict running untrusted WebAssembly modules on ARM64 systems meanwhile.

First seen: 26 Oct 2026
Last update: 26 Oct 2026, 11:52 UTC
Source: news
On the menu as: Rust & WebAssembly

Check this repository for exposure to one security incident from pwned.coffee. Report first, change nothing until I say so.

## Wasmtime: sandbox escape
Severity: unknown. Patch status: fix status unknown.
Affected: Wasmtime

Two critical flaws in Wasmtime could allow a malicious WebAssembly module to escape the sandbox, affecting ARM64 systems.

## Steps
1. Search the repo, its CI and infra config for Wasmtime. If present, report the version in use and whether it's affected.
2. No source names a fix yet; check the vendor advisory. Until one ships: restrict network access to it.

## Report
A table: file, product or package, version in use, affected yes/no, exact fix. Then anything a human has to check outside the repo.

If you have the pwned.coffee MCP server (https://pwned.coffee/mcp), call lookup_cve for the latest, and check_repo with this repo's lockfiles, Dockerfiles and workflows for a full receipt.
Sources: https://thehackernews.com/2026/10/two-critical-wasmtime-flaws-could-let.html
https://pwned.coffee/i/wasmtime-sandbox-escape

Timeline

26 Oct 2026, 13:17 UTC
Fix status: patched → unknown.
26 Oct 2026
First reported.

Receipt

Exploitation: No known exploitation
Score: No CVSS published yet: severity unknown.
Last checked: 26 Oct 2026, 15:17 UTC

Sources: KEV – CVE record – Vendor –

Sources

feeds.feedburner.com: Two Critical Wasmtime Flaws Could Let Malicious WebAssembly Modules Escape Sandboxes

Wrong fix version, or a source we missed? Send it back to chef@pwned.coffee with the source, and we'll correct it here.

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