Improper Validation of Unsafe Equivalence in Input Affecting @node-oauth/oauth2-server package, versions <5.3.0
Threat Intelligence
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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- published5 May 2026
- disclosed16 Apr 2026
- creditKarimTantawey
Introduced: 16 Apr 2026
CVE-2026-41213 (opens in a new tab)How to fix?
Upgrade @node-oauth/oauth2-server to version 5.3.0 or higher.
Overview
@node-oauth/oauth2-server is a Complete, framework-agnostic, compliant and well tested module for implementing an OAuth2 Server in node.js
Affected versions of this package are vulnerable to Improper Validation of Unsafe Equivalence in Input in the token process. An attacker can obtain unauthorized access to bearer tokens by brute-forcing weak or invalid code_verifier values during the PKCE token exchange, especially if an authorization code has been intercepted. This is possible because the server does not enforce RFC7636 requirements for the code_verifier and does not revoke the authorization code after failed attempts, allowing repeated online guesses.