In the afternoon on Friday, March 14, 2025, details began to emerge about a serious security exploit on a popular GitHub Action called changed files (tj-actions/changed-files). About 23,000 GitHub repos use this Action as part of their CI and DevOps workflows. It allows you to track which files have changed across branches and commits. An attacker with write privileges on the Action repo made a commit that caused encrypted secrets to appear in plaintext in the GitHub Action logs.