CVE-2019-16109 is a medium-severity (CVSS 5.3) vulnerability in devise. A fix is available for devise — see the affected versions and patch details below.
Authentication Bypass in Devise
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
Where this sits among everything scored
Real-World Exposure
deviseReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects RubyGems packages — download data is not available via public APIs for these ecosystems.
Description
An issue was discovered in Plataformatec Devise before 4.7.1. It confirms accounts upon receiving a request with a blank confirmation_token, if a database record has a blank value in the confirmation_token column. (However, there is no scenario within Devise itself in which such database records would exist.)
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 💎RubyGems | devise | all versions | 4.7.1bundle update devise --conservative |
Affected Products
deviseplataformatecDetection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for devise, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update devise to 4.7.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2019-16109 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
Frequently Asked Questions
Is CVE-2019-16109 in your dependencies?
Find it across RubyGems, including transitive dependencies.