CVE-2026-41213 — MEDIUM (5.9)

Vulnerability Description

@node-oauth/oauth2-server is a module for implementing an OAuth2 server in Node.js. The token exchange path accepts RFC7636-invalid code_verifier values (including one-character strings) for S256 PKCE flows. Because short/weak verifiers are accepted and failed verifier attempts do not consume the authorization code, an attacker who intercepts an authorization code can brute-force code_verifier guesses online until token issuance succeeds.

CVSS Score

5.9

MEDIUM

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N

Attack Vector

NETWORK

Attack Complexity

HIGH

Privileges Required

NONE

User Interaction

NONE

Scope

UNCHANGED

Confidentiality

HIGH

Integrity

NONE

Availability

NONE

Related Weaknesses (CWE)

CWE-307 CWE-1289

References

FAQ

What is CVE-2026-41213?

CVE-2026-41213 is a vulnerability with a CVSS score of 5.9 (MEDIUM). @node-oauth/oauth2-server is a module for implementing an OAuth2 server in Node.js. The token exchange path accepts RFC7636-invalid code_verifier values (including one-character strings) for S256 PKCE...

How severe is CVE-2026-41213?

CVE-2026-41213 has been rated MEDIUM with a CVSS base score of 5.9/10. Review the CVSS metrics above for detailed severity breakdown.

Is there a patch for CVE-2026-41213?

Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.