Ruby gems: code execution

Ruby gems

Ruby gems can run code on install and on every gem command, even gem list.

Do this now

Check the vendor advisory for a Ruby gems fix and avoid installing untrusted gems meanwhile.

Who should check: teams running Ruby / Rails

First seen: 5 Nov 2026
Last update: 5 Nov 2026, 22:19 UTC
Source: news
On the menu as: Ruby / Rails

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

## Ruby gems: code execution
Severity: unknown. Patch status: fix status unknown.
Affected: Ruby gems

Ruby gems can run code on install and on every gem command, even gem list.

## Steps
1. Search the repo, its CI and infra config for Ruby gems. 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://www.aikido.dev/blog/gem-list-runs-someone-elses-code
https://pwned.coffee/i/ruby-gems-code-execution

Receipt

Exploitation: No known exploitation
Score: No CVSS published yet: severity unknown.
Last checked: 6 Nov 2026, 12:18 UTC

Sources: KEV – CVE record – Vendor –

Sources

aikido.dev: Even gem list can run someone else's code

Follow on X

Totalone coffee