The vulnerability occurs when the Git resolver in Tekton Pipelines operates in API mode and the user omits the token parameter. Under these conditions, the resolver inadvertently sends the system‑configured Git API token—such as a GitHub personal access token or GitLab token—to the serverURL supplied by the user. This leak constitutes an unintended information exposure (CWE‑201) and can allow an attacker to obtain a credential that is generally trusted to perform actions on the developer’s behalf, potentially leading to downstream compromise of source‑code repositories or other services that rely on the token.

The flaw affects the Tekton Pipelines product, versions 1.0.0 through 1.10.0. A tenant who has permission to create a TaskRun or PipelineRun can exploit this and direct the resolver to an attacker‑controlled endpoint to capture the API token.

The CVSS score of 7.7 indicates high impact for the affected users. Although the EPSS score is not publicly available and the vulnerability is not listed in the CISA KEV catalog, the attack vector requires local cluster access to create a run and a configurable serverURL. An attacker with the necessary permissions can directly exfiltrate the token, enabling unauthorized access to Git services. While exploitation is straightforward for an internal attacker, external exploitation would need a foothold with sufficient permissions.