Vulnerability Description
Feathersjs is a framework for creating web APIs and real-time applications with TypeScript or JavaScript. In versions 5.0.39 and below, all HTTP request headers are stored in the session cookie, which is signed but not encrypted, exposing internal proxy/gateway headers to clients. The OAuth service stores the complete headers object in the session, then the session is persisted using cookie-session, which base64-encodes the data. While the cookie is signed to prevent tampering, the contents are readable by anyone by simply decoding the base64 value. Under specific deployment configurations (e.g., behind reverse proxies or API gateways), this can lead to exposure of sensitive internal infrastructure details such as API keys, service tokens, and internal IP addresses. This issue has been fixed in version 5.0.40.
CVSS Score
MEDIUM
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Feathersjs | Feathers | < 5.0.40 |
Related Weaknesses (CWE)
References
- https://github.com/feathersjs/feathers/commit/ee19a0ae9bc2ebf23b1fe598a1f7361981Patch
- https://github.com/feathersjs/feathers/releases/tag/v5.0.40ProductRelease Notes
- https://github.com/feathersjs/feathers/security/advisories/GHSA-9m9c-vpv5-9g85Third Party Advisory
FAQ
What is CVE-2026-27193?
CVE-2026-27193 is a vulnerability with a CVSS score of 5.3 (MEDIUM). Feathersjs is a framework for creating web APIs and real-time applications with TypeScript or JavaScript. In versions 5.0.39 and below, all HTTP request headers are stored in the session cookie, which...
How severe is CVE-2026-27193?
CVE-2026-27193 has been rated MEDIUM with a CVSS base score of 5.3/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-27193?
Check the references section above for vendor advisories and patch information. Affected products include: Feathersjs Feathers.