Jenkins OpenId Connect Authentication Plugin 4.452.v2849b_d3945fa_ and earlier, except 4.438.440.v3f5f201de5dc, treats usernames as case-insensitive, allowing attackers on Jenkins instances configured with a case-sensitive OpenID Connect provider to log in as any user by providing a username that differs only in letter case, potentially gaining administrator access to Jenkins.

Jenkins OpenId Connect Authentication Plugin 4.418.vccc7061f5b_6d and earlier does not invalidate the previous session on login.

Jenkins OpenId Connect Authentication Plugin 4.354.v321ce67a_1de8 and earlier does not check the `iss` (Issuer) claim of an ID Token, allowing attackers to subvert the authentication flow, potentially gaining administrator access to Jenkins.

Jenkins OpenId Connect Authentication Plugin 4.354.v321ce67a_1de8 and earlier does not check the `aud` (Audience) claim of an ID Token, allowing attackers to subvert the authentication flow, potentially gaining administrator access to Jenkins.