Elo: sandbox escape to code execution

Elo (@enspirit/elo)

An unauthenticated attacker who controls a string passed to any Elo JavaScript-emission path — defaultFormats.elo.parse(), the bin/elo CLI, or the live browser playground at elo-lang.org/try — can execute arbitrary code in the host JavaScript runtime.

Do this now

Check the Elo advisory for a fix and don't pass untrusted strings to Elo's parse, CLI or playground meanwhile.

First seen: 3 Nov 2026
Last update: 3 Nov 2026, 18:18 UTC
Versions per GitHub advisory, not the vendor: @enspirit/elo 1.0.1
Identifiers: CVE-2026-44267
CVSS: 9.8
Source: GitHub advisory
On the menu as: npm packages

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

## Elo: sandbox escape to code execution
Severity: critical. Patch status: fix status unknown.
Affected: Elo (@enspirit/elo)
Versions per GitHub advisory, not the vendor: @enspirit/elo 1.0.1
Ids: CVE-2026-44267

An unauthenticated attacker who controls a string passed to any Elo JavaScript-emission path — defaultFormats.elo.parse(), the bin/elo CLI, or the live browser playground at elo-lang.org/try — can execute arbitrary code in the host JavaScript runtime.

## Steps
1. Search every lockfile and manifest (package-lock.json, yarn.lock, pnpm-lock.yaml, requirements*.txt, poetry.lock, uv.lock, composer.lock, go.sum, Cargo.lock, Gemfile.lock) for `@enspirit/elo`. For each hit, compare the installed version with the version on the same major line (per GitHub advisory, not the vendor, so check the vendor's advisory before treating it as a fix): @enspirit/elo 1.0.1. If it's lower, give the exact upgrade command for the package manager this repo uses.
2. Versions per GitHub advisory, not the vendor: @enspirit/elo: <= 1.0.0 → 1.0.1. Elo (@enspirit/elo): 1.0.1. Don't treat them as a fix until the vendor says so.

## Fix by release line
| Line | State | Fix | Until then |
|---|---|---|---|
| @enspirit/elo <= 1.0.0 | per GitHub advisory, not the vendor | 1.0.1 | restrict network access to it |
| Elo (@enspirit/elo) | per the CVE record from GitHub_M, not the vendor | 1.0.1 | 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("CVE-2026-44267") for the latest, and check_repo with this repo's lockfiles, Dockerfiles and workflows for a full receipt.
Sources: https://github.com/advisories/GHSA-33r5-xmm8-v6x5 https://github.com/enspirit/elo/security/advisories/GHSA-33r5-xmm8-v6x5
https://pwned.coffee/i/elo-javascript-emitter-has-sandbox-escape-to-arbitrary-n-cve-2026-44267

Timeline

3 Nov 2026, 18:18 UTC
Fix status: patched → unknown.
3 Nov 2026
First reported.

Receipt

Exploitation: No known exploitation
Checked by hand “The CVE record names enspirit's elo and the GitHub advisory the npm package @enspirit/elo: the flaw is in Elo, and Node.js only runs the code it emits.” source
By release line, per GitHub advisory, not the vendor: Product Affected Version named Source
@enspirit/elo (npm) <= 1.0.0 1.0.1 GitHub advisory per GitHub advisory, not the vendor checked 3 Nov
Elo (@enspirit/elo) before 1.0.1 1.0.1 CVE record (CNA) per the CVE record from GitHub_M, not the vendor checked 3 Nov
Score: CVSS 9.8 (critical). CVSS 3.1 9.8 (CNA GitHub_M) for CVE-2026-44267
Last checked: 4 Nov 2026, 08:18 UTC

Product	Affected	Version named	Source
@enspirit/elo (npm)	<= 1.0.0	1.0.1	GitHub advisory per GitHub advisory, not the vendor checked 3 Nov
Elo (@enspirit/elo)	before 1.0.1	1.0.1	CVE record (CNA) per the CVE record from GitHub_M, not the vendor checked 3 Nov

Sources: KEV – CVE record ✓ Vendor –

Sources

Totalone very hot coffee