An issue was discovered in the rack-cors (aka Rack CORS Middleware) gem before 1.0.4 for…
Priority LOW 29CWE-22Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Information disclosure
- Confidentiality · integrity · availability
- Low · None · None
- Fix status
- Fixed
Attack profile from CVSS 3.1 · NVD. Fix status from CNA and GitHub. Impact type from CWE-22 and the CVSS impact.
Summary
An issue was discovered in the rack-cors (aka Rack CORS Middleware) gem before 1.0.4 for Ruby. It allows ../ directory traversal to access private resources because resource matching does not ensure that pathnames are in a canonical format.
Why it matters now
EPSS 0.02462 84th percentileScored 2026-11-07
Fix Fixed rack-cors (RubyGems): 1.0.4
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| — | — | all versions | — | No fix listed | CNA |
| — | rack-cors (RubyGems) | before 1.0.4 | 1.0.4 | Patch available | GHSA-pf8f-w267-mq2h |
- — Vendor— Affected all versions Fixed in — No fix listed CNA
- rack-cors (RubyGems) Vendor— Affected before 1.0.4 Fixed in 1.0.4 Patch available GHSA-pf8f-w267-mq2h
CPE configurations NVD · 5
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:rack-cors_project:rack-cors:*:*:*:*:*:ruby:*:* | before 1.0.4 | Vulnerable | Rack-cors Project |
| cpe:2.3:o:debian:debian_linux:8.0:*:*:*:*:*:*:* | 8.0 | Vulnerable | Debian |
| cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:* | 9.0 | Vulnerable | Debian |
| cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:* | 10.0 | Vulnerable | Debian |
| cpe:2.3:o:canonical:ubuntu_linux:16.04:*:*:*:esm:*:*:* | 16.04 | Vulnerable | Canonical |
- cpe:2.3:a:rack-cors_project:rack-cors:*:*:*:*:*:ruby:*:* Versions before 1.0.4 Vulnerable ·Rack-cors Project
- cpe:2.3:o:debian:debian_linux:8.0:*:*:*:*:*:*:* Versions 8.0 Vulnerable ·Debian
- cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:* Versions 9.0 Vulnerable ·Debian
- cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:* Versions 10.0 Vulnerable ·Debian
- cpe:2.3:o:canonical:ubuntu_linux:16.04:*:*:*:esm:*:*:* Versions 16.04 Vulnerable ·Canonical
Remediation
- Fix · GHSA-pf8f-w267-mq2h rack-cors (RubyGems) Fixed in 1.0.4 Advisory →
Vendor assessments
Timeline
- 2026-10-02 Threatist record created from CVE-2019-18978
- 2026-10-03 Alias added: GHSA-pf8f-w267-mq2h
References
Patch 2
Advisory 5
Sources
- CVE-2019-18978 · CVE Program
- CVE-2019-18978 · NVD
- FIRST EPSS
- GHSA-pf8f-w267-mq2h · GitHub Advisory Database · CC BY 4.0
- CVE-2019-18978 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences