CVE-2019-25766 in Renovate
Summary
by MITRE • 08/19/2026
Renovate versions >= 13.87.0 and <= 19.38.6 leak temporary repository tokens into pull request comments during certain Go Modules update failure scenarios. The issue is fixed in version 19.38.7. Anyone able to view the affected pull request comments could obtain the exposed tokens.
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Analysis
by VulDB Data Team • 08/19/2026
The vulnerability identified as a token leakage flaw within Renovate, specifically affecting versions from 13.87.0 through 19.38.6, represents a significant security risk in automated dependency update workflows. This issue manifests when the tool attempts to process updates for Go Modules and encounters specific failure scenarios during the repository initialization or configuration phase. In these error conditions, Renovate inadvertently includes temporary authentication tokens within the comments generated on pull requests intended to propose code changes. These tokens are typically short-lived credentials designed to grant limited access to version control systems or package registries, but their exposure in publicly visible or team-accessible comment threads undermines the principle of least privilege and compromises the integrity of the CI/CD pipeline infrastructure.
From a technical perspective, this flaw is classified under CWE-798: Use of Hard-coded Credentials, although it involves dynamically generated temporary tokens rather than static secrets. The root cause lies in how error handling routines construct log messages or user-facing notifications without sanitizing sensitive authentication data embedded within the underlying API responses or internal state objects. When a Go module update fails due to network issues, permission errors, or malformed package definitions, the exception handler captures context that includes these temporary tokens and appends them directly to the pull request comment body. This behavior violates standard security practices for error reporting, which dictate that sensitive data must be redacted before being exposed in user interfaces or logs.
The operational impact of this vulnerability is substantial because it allows any individual with read access to the affected repository's pull requests to harvest these temporary tokens. Once obtained, an attacker could potentially use these credentials to authenticate against the associated version control platform or package registry. Depending on the permissions granted by the token, this could lead to unauthorized code pushes, modification of existing branches, exfiltration of private source code, or injection of malicious dependencies into downstream projects that consume the compromised modules. In environments where Renovate is integrated with sensitive internal repositories, this leakage can serve as an initial foothold for further lateral movement within the organization's infrastructure.
This vulnerability aligns with MITRE ATT&CK technique T1528: Steal Application Access Token, which describes adversaries stealing application access tokens to maintain persistence or escalate privileges without needing user credentials. The exposure of these tokens facilitates unauthorized access and can be leveraged in conjunction with other tactics such as T1078: Valid Accounts if the stolen token provides valid authentication for subsequent attacks. Organizations relying on Renovate must recognize that even temporary, scoped tokens carry significant risk when exposed outside their intended secure context, particularly in collaborative environments where pull request visibility is broad.
To mitigate this vulnerability, immediate action should be taken to upgrade Renovate to version 19.38.7 or later, which contains the necessary patches to prevent token leakage during error handling sequences for Go Modules and other package managers. In addition to upgrading, organizations should audit recent pull requests in repositories using affected versions to identify any exposed tokens. If exposure is confirmed, those specific credentials must be rotated immediately by revoking them through the respective identity provider or version control system API. Furthermore, security teams should implement monitoring alerts for unusual authentication patterns originating from compromised token ranges and enforce strict access controls on repository comments where sensitive data might inadvertently appear during automated processes.