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CVE-2026-41213

@node-oauth/oauth2-server: PKCE code_verifier ABNF not enforced in token exchange allows brute-force redemption of intercepted authorization codes PUBLISHED

Description (CNA)

@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.

Affected (CNA)

Vendor / productVersions
node-oauth / node-oauth2-serveraffected < 5.3.0

CWE

CWE-307, CWE-1289

References

ADP enrichment

CISA-ADP

No English description supplied.