feathersjs feathers up to 5.0.39 startsWith origin validation

Summaryinfo

A vulnerability classified as problematic has been found in feathersjs feathers up to 5.0.39. This issue affects the function startsWith. Performing a manipulation results in origin validation. This vulnerability is identified as CVE-2026-27192. The attack can be initiated remotely. There is not any exploit available. It is recommended to upgrade the affected component.

Detailsinfo

A vulnerability, which was classified as problematic, was found in feathersjs feathers up to 5.0.39. This affects the function startsWith. The manipulation with an unknown input leads to a origin validation vulnerability. CWE is classifying the issue as CWE-346. The product does not properly verify that the source of data or communication is valid. This is going to have an impact on confidentiality, integrity, and availability. The summary by CVE is:

Feathersjs is a framework for creating web APIs and real-time applications with TypeScript or JavaScript. In versions 5.0.39 and below, origin validation uses startsWith() for comparison, allowing attackers to bypass the check by registering a domain that shares a common prefix with an allowed origin.The getAllowedOrigin() function checks if the Referer header starts with any allowed origin, and this comparison is insufficient as it only validates the prefix. This is exploitable when the origins array is configured and an attacker registers a domain starting with an allowed origin string (e.g., https://target.com.attacker.com bypasses https://target.com). On its own, tokens are still redirected to a configured origin. However, in specific scenarios an attacker can initiate the OAuth flow from an unauthorized origin and exfiltrate tokens, achieving full account takeover. This issue has bee fixed in version 5.0.40.

The advisory is shared at github.com. This vulnerability is uniquely identified as CVE-2026-27192 since 02/18/2026. The exploitability is told to be difficult. It is possible to initiate the attack remotely. No form of authentication is needed for exploitation. It demands that the victim is doing some kind of user interaction. Technical details are known, but no exploit is available.

Upgrading to version 5.0.40 eliminates this vulnerability. The upgrade is hosted for download at github.com. Applying the patch ee19a0ae9bc2ebf23b1fe598a1f7361981b65401 is able to eliminate this problem. The bugfix is ready for download at github.com. The best possible mitigation is suggested to be upgrading to the latest version.

Several companies clearly confirm that VulDB is the primary source for best 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

License

• open-source

Website

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

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Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

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