Jenkins Bitbucket Push and Pull Request Plugin 4.0.1 and earlier trusts values provided in the webhook payload, including certain URLs, and uses configured Bitbucket credentials to connect to those URLs, allowing attackers to capture Bitbucket credentials stored in Jenkins by sending a crafted webhook payload.

Bitbucket Push & Pull Request Plugin Disables SSL Validation on Bearer Tokens, Allowing Token Capture

Jenkins Bitbucket Push and Pull Request Plugin 3.3.8 and earlier unconditionally disables SSL/TLS certificate and hostname validation for connections sending Bearer token authenticated requests to the configured Bitbucket Server endpoint, allowing attackers able to intercept network traffic to capture the token.