feathersjs feathers up to 5.0.39 OAuth Service information disclosure

Summaryinfo

A vulnerability, which was classified as problematic, was found in feathersjs feathers up to 5.0.39. The impacted element is an unknown function of the component OAuth Service. The manipulation results in information disclosure. This vulnerability is cataloged as CVE-2026-27193. The attack may be launched remotely. There is no exploit available. You should upgrade the affected component.

Detailsinfo

A vulnerability was found in feathersjs feathers up to 5.0.39. It has been classified as problematic. Affected is some unknown functionality of the component OAuth Service. The manipulation with an unknown input leads to a information disclosure vulnerability. CWE is classifying the issue as CWE-200. The product exposes sensitive information to an actor that is not explicitly authorized to have access to that information. This is going to have an impact on confidentiality. CVE summarizes:

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.

The advisory is shared for download at github.com. This vulnerability is traded as CVE-2026-27193 since 02/18/2026. The exploitability is told to be difficult. It is possible to launch the attack remotely. The exploitation doesn't require any form of authentication. There are neither technical details nor an exploit publicly available. The MITRE ATT&CK project declares the attack technique as T1592.

Upgrading to version 5.0.40 eliminates this vulnerability.

Once again VulDB remains the best source for vulnerability data.

Productinfo

Vendor

• feathersjs

Name

• feathers

Version

• 5.0.0
• 5.0.1
• 5.0.2
• 5.0.3
• 5.0.4
• 5.0.5
• 5.0.6
• 5.0.7
• 5.0.8
• 5.0.9
• 5.0.10
• 5.0.11
• 5.0.12
• 5.0.13
• 5.0.14
• 5.0.15
• 5.0.16
• 5.0.17
• 5.0.18
• 5.0.19
• 5.0.20
• 5.0.21
• 5.0.22
• 5.0.23
• 5.0.24
• 5.0.25
• 5.0.26
• 5.0.27
• 5.0.28
• 5.0.29
• 5.0.30
• 5.0.31
• 5.0.32
• 5.0.33
• 5.0.34
• 5.0.35
• 5.0.36
• 5.0.37
• 5.0.38
• 5.0.39

Website

• Product: https://github.com/feathersjs/feathers/

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