CVE-2025-27610 is a high-severity (CVSS 7.5) CWE-23 vulnerability in rack. A fix is available for rack — see the affected versions and patch details below.
Local File Inclusion in Rack::Static
Exploitation Status
No confirmed exploitation observed yet
- CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for CVE-2025-27610.
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.
How urgent is this, really
CVE-2025-27610 plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 378,567 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
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 | 2.2.13bundle update rack --conservative |
| 💎RubyGems | rack | ≥ 3.0&&< 3.0.14 | 3.0.14bundle update rack --conservative |
| 💎RubyGems | rack | ≥ 3.1&&< 3.1.12 | 3.1.12bundle update rack --conservative |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for rack, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
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 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2025-27610 can be triaged on real exposure rather than presence alone.
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.
Fixing This On Your OS
If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.
This is an Important vulnerability because it allows attackers to bypass `urls:` restrictions and access unintended files under the `root:` directory using encoded path traversal. Since `Rack::Static` is often used to serve public assets, any sensitive files within the same root—like credentials, configs, or source…
| Product | Fixed in | Advisory |
|---|---|---|
| Red Hat Satellite 6.14 for RHEL 8 | rubygem-rack-0:2.2.13-1.el8sat | RHSA-2025:3492 |
| Red Hat Satellite 6.15 for RHEL 8 | rubygem-rack-0:2.2.13-1.el8sat | RHSA-2025:3491 |
| Red Hat Satellite 6.16 for RHEL 8 | rubygem-rack-0:2.2.13-1.el8sat | RHSA-2025:3490 |
| Red Hat Satellite 6.17 for RHEL 9 | rubygem-rack-0:2.2.13-1.el9sat | RHSA-2025:4576 |
| RHOL-5.8-RHEL-9 | openshift-logging/cluster-logging-operator-bundle:v5.8.19-26 | RHSA-2025:3448 |
| RHOL-5.9-RHEL-9 | openshift-logging/cluster-logging-operator-bundle:v5.9.13-22 | RHSA-2025:3906 |
Frequently Asked Questions
Is CVE-2025-27610 in your dependencies?
O3 Security finds CVE-2025-27610 across RubyGems dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.