CVE-2026-27192
published 2026-02-21CVE-2026-27192: 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…
PriorityP348high8.1CVSS 3.1
AVNACHPRNUINSUCHIHAH
EPSS
0.24%
15.0th percentile
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.
Affected
2 ranges
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| feathersjs | authentication-oauth | >= 0 < 5.0.40 | 5.0.40 |
| feathersjs | feathers | < 5.0.40 | 5.0.40 |
CVSS provenance
nvdv3.18.1HIGHCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
nvdv4.07.6HIGHCVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:P/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
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GHSA
Feathers has an origin validation bypass via prefix matching
ghsa·2026-02-19
CVE-2026-27192 [HIGH] CWE-346 Feathers has an origin validation bypass via prefix matching
Feathers has an origin validation bypass via prefix matching
The 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:
```javascript
// https://github.com/feathersjs/feathers/blob/dove/packages/authentication-oauth/src/strategy.ts#L75
const allowedOrigin = origins.find((current) => referer.toLowerCase().startsWith(current.toLowerCase()));
```
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` byp
OSV
Feathers has an origin validation bypass via prefix matching
osv·2026-02-19
CVE-2026-27192 [HIGH] Feathers has an origin validation bypass via prefix matching
Feathers has an origin validation bypass via prefix matching
The 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:
```javascript
// https://github.com/feathersjs/feathers/blob/dove/packages/authentication-oauth/src/strategy.ts#L75
const allowedOrigin = origins.find((current) => referer.toLowerCase().startsWith(current.toLowerCase()));
```
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` byp
No detection rules found.
No public exploits indexed.
2026-02-21
Published