EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
Blast Radius
rack💎rack💎rackReal-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
Rack provides an interface for developing web applications in Ruby. Prior to versions 2.2.13, 3.0.14, and 3.1.12, Rack::Static can serve files under the specified root: even if urls: are provided, which may expose other files under the specified root: unexpectedly. The vulnerability occurs because Rack::Static does not properly sanitize user-supplied paths before serving files. Specifically, encoded path traversal sequences are not correctly validated, allowing attackers to access files outside the designated static file directory. By exploiting this vulnerability, an attacker can gain access to all files under the specified root: directory, provided they are able to determine then path of the file. Versions 2.2.13, 3.0.14, and 3.1.12 contain a patch for the issue. Other mitigations include removing usage of Rack::Static, or ensuring that root: points at a directory path which only contains files which should be accessed publicly. It is likely that a CDN or similar static file server would also mitigate the issue.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 💎RubyGems | rack | all versions | 2.2.13 |
| 💎RubyGems | rack | ≥ 3.0&&< 3.0.14 | 3.0.14 |
| 💎RubyGems | rack | ≥ 3.1&&< 3.1.12 | 3.1.12 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for rack. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update rack to 2.2.13 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2025-27610 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.
How O3 protects you
O3 pinpoints whether CVE-2025-27610 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to CVE-2025-27610. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2025-27610 in your dependencies?
O3 detects CVE-2025-27610 across RubyGems dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.