CVE-2026-49265

OAuthLib is an implementation of the OAuth request-signing logic for Python 3.6+. From 3.0.0 until 4.0.0, OAuthLib's PKCE checks in oauthlib/oauth2/rfc6749/granttypes/authorizationcode.py compare attacker-supplied codeverifier values with stored challenges using ordinary string equality in...

CVE-2026-49265 OAuthLib: Timing Attack Vulnerability in PKCE code_verifier Comparison

OAuthLib is an implementation of the OAuth request-signing logic for Python 3.6+. From 3.0.0 until 4.0.0, OAuthLib's PKCE checks in oauthlib/oauth2/rfc6749/granttypes/authorizationcode.py compare attacker-supplied codeverifier values with stored challenges using ordinary string equality in...

PYSEC-2026-4114 Oauthlib: Timing Attack Vulnerability in PKCE code_verifier Comparison (CWE-208)

Summary A timing side-channel vulnerability exists in the PKCE RFC 7636 implementation of the Authorization Code Grant flow. The codechallengemethodplain function uses Python's standard == operator for string comparison instead of a constant-time comparison function, potentially allowing...

Oauthlib: Timing Attack Vulnerability in PKCE code_verifier Comparison (CWE-208)

SummaryA timing side-channel vulnerability exists in the PKCE RFC 7636 implementation of the Authorization Code Grant flow. The codechallengemethodplain function uses Python's standard == operator for string comparison instead of a constant-time comparison function, potentially allowing...

CVE-2026-49265

A timing side-channel vulnerability exists in the PKCE RFC 7636 implementation of the Authorization Code Grant flow. The "codechallengemethodplain" function uses Python's standard "==" operator for string comparison instead of a constant-time comparison function, potentially allowing timing-based...

Timing Attack

Overview Affected versions of this package are vulnerable to Timing Attack via the codechallengemethods256 and codechallengemethodplain functions in oauthlib/oauth2/rfc6749/granttypes/authorizationcode.py, which compare PKCE code verifiers and challenges using the non-constant-time == operator. A...

GHSA-XPV3-W29H-X7CV Oauthlib: Timing Attack Vulnerability in PKCE code_verifier Comparison (CWE-208)

Summary A timing side-channel vulnerability exists in the PKCE RFC 7636 implementation of the Authorization Code Grant flow. The codechallengemethodplain function uses Python's standard == operator for string comparison instead of a constant-time comparison function, potentially allowing...

Oauthlib: Timing Attack Vulnerability in PKCE code_verifier Comparison (CWE-208)

Summary A timing side-channel vulnerability exists in the PKCE RFC 7636 implementation of the Authorization Code Grant flow. The codechallengemethodplain function uses Python's standard == operator for string comparison instead of a constant-time comparison function, potentially allowing...