Ruby on Rails: critical flaw

Ruby on Rails

Critical flaw in Ruby on Rails allows attackers to write server files via crafted ImageMagick uploads

Do this now

Check the Ruby on Rails security advisory for a fix and restrict uploads to trusted users while you wait.

First seen: 4 Nov 2026
Last update: 4 Nov 2026, 12:17 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 on Rails: critical flaw
Severity: unknown. Patch status: fix status unknown.
Affected: Ruby on Rails

Critical flaw in Ruby on Rails allows attackers to write server files via crafted ImageMagick uploads

## Steps
1. Search the repo, its CI and infra config for Ruby on Rails. 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/2026/11/critical-rails-flaw-lets-attackers.html
https://pwned.coffee/i/ruby-on-rails-critical-flaw

Timeline

4 Nov 2026, 12:17 UTC
Fix status: patched → unknown.
4 Nov 2026
First reported.

Receipt

Exploitation: No known exploitation
Score: No CVSS published yet: severity unknown.
Last checked: 4 Nov 2026, 13:17 UTC

Sources: KEV – CVE record – Vendor –

Sources

feeds.feedburner.com: Critical Rails Flaw Lets Attackers Write Server Files via Crafted ImageMagick Uploads

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