CVE-2026-12171: CWE-829: Inclusion of Functionality from Untrusted Control Sphere in cookpete auto-changelog

The vulnerability in auto-changelog before version 2.6.1 arises because it merges configuration from the target repository (such as the .auto-changelog file and the auto-changelog key in package.json) into its runtime options without sufficient trust validation. This includes honoring security-sensitive options like handlebarsSetup, which is passed to require(), enabling execution of arbitrary code from attacker-controlled repositories. Additional attack vectors include loading malicious plugins, git argument injection allowing arbitrary file writes, and making outbound requests to attacker-controlled URLs. The issue is mitigated in version 2.6.1 by treating in-repository configuration as untrusted and refusing to run when these options are set unless the user explicitly opts in with the --unsafe-config flag.

An attacker who controls repository content can execute arbitrary code with the privileges of the user or CI job running auto-changelog. This includes access to workflow secrets and the ability to write arbitrary files or make outbound network requests. The vulnerability affects scenarios such as running auto-changelog on untrusted pull request heads or third-party repositories without installed dependencies.

Upgrade to auto-changelog version 2.6.1 or later, which treats in-repository configuration as untrusted and refuses to run when security-sensitive options are set unless explicitly overridden with the --unsafe-config flag. Avoid running auto-changelog on untrusted repository content without this upgrade. Patch status is confirmed by the vendor's release of version 2.6.1.