CVE-2026-12171: auto-changelog: code execution via untrusted in-repository configuration (handlebarsSetup/plugins), plus argument injection, path traversal, and SSRF

Severity: high (CVSS 7.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-10-05 · updated 2026-10-06
Weakness: CWE-22

Description

auto-changelog before 2.6.1 merges configuration from inside the target repository (the .auto-changelog file and the auto-changelog key in package.json) into its options, and honors security-sensitive options from that untrusted source. The handlebarsSetup option is passed to require(), so running auto-changelog over attacker-controlled repository content (for example, in a CI workflow that checks out an untrusted pull request head, or locally on a forked or third-party repository) executes attacker-chosen code with the privileges of the invoking user or CI job, including access to workflow secrets, without the repository dependencies ever being installed. The plugins option similarly loads attacker-controlled modules from the repository. Under the same conditions, appendGitLog/appendGitTag allow git argument injection (e.g. --output= to write arbitrary files), output allows writing attacker-influenced content to arbitrary paths, and template causes an outbound request to an attacker-chosen URL. Version 2.6.1 treats in-repository configuration as untrusted and refuses to run when it sets these options, unless the new --unsafe-config flag is passed.

Affected products

cookpete auto-changelog: before 2.6.1 — fixed in 2.6.1

How to fix

Upgrade to a fixed version: cookpete auto-changelog 2.6.1. Check the vendor advisory for mitigations.

References

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