CVE-2026-27192

What it 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.

At a glance

Exploitability

Can be exploited over the network without logging in, but needs a user to act. High risk of data exposure, data tampering.

Exploit odds

0.3% chance of exploitation in the next 30 days (EPSS).

Fix

A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

1. 2026-02-21 04:15 UTC PublishedDisclosed publicly on CVE.org and NVD
2. 2026-06-17 10:26 UTC Last updatedMost recent change to the record

Why it ranks here

• Exploited in the wild: no, CISA does not list it.
• Exploit odds: 0.3% in the next 30 days (EPSS).
• Severity: 7.6 HIGH (CVSS).
• Fix: a patch or advisory is linked.

Details

Published

2026-02-21 04:15 UTC

Last modified

2026-06-17 10:26 UTC

Exploit probability

0.3% · EPSS, next 30 days

Weakness

CWE-346

Record status

Analyzed

Affected

• Feathersjs Feathers < 5.0.40

Attack profile CVSS 4.0 · 7.6

Attack vector

Network

Complexity

High

Attack requirements

None

Privileges needed

None

User interaction

Passive

Confidentiality

High

Integrity

High

Availability

None

Is it in your code?

Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.

Read https://cve-list.com/agent/cve/CVE-2026-27192.md and follow it. Check whether this project is affected by CVE-2026-27192. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.

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