CVE-2017-18076 is a high-severity (CVSS 7.5) vulnerability in omniauth. A fix is available for omniauth — see the affected versions and patch details below.
Omniauth allows POST parameters to be stored in session
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
omniauthReal-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
In strategy.rb in OmniAuth before 1.3.2, the authenticity_token value is improperly protected because POST (in addition to GET) parameters are stored in the session and become available in the environment of the callback phase.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 💎RubyGems | omniauth | all versions | 1.3.2bundle update omniauth --conservative |
Affected Products
debian linuxdebianomniauthomniauthDetection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for omniauth, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update omniauth to 1.3.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2017-18076 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-2017-18076 in your dependencies?
Find it across RubyGems, including transitive dependencies.