GitHub Actions Update Blocks Unsafe PR Checkouts Amid Workflow Injection Risks

GitHub released actions/checkout@v7 with a new default safeguard that blocks unsafe checkouts of code from untrusted pull requests in privileged pull_request_target and some workflow_run scenarios. The change is designed to stop common “pwn request” patterns that can expose a repository’s GITHUB_TOKEN, secrets, cache access, and runner environment when workflows fetch and execute attacker-controlled fork code. GitHub said the protection is available immediately in v7 and will be backported to supported major versions, while narrowly pinned deployments must be updated manually.

The move follows years of warnings about GitHub Actions supply-chain abuse and fresh examples showing how workflow misconfigurations can lead to token theft, cache poisoning, OIDC token abuse, and malicious package publication. Separately, a disclosed advisory tracked as GHSA-C3XH-98XP-6QHF described a command-injection flaw in a GitHub Actions workflow where an attacker could open an issue on a public repository with a crafted title and trigger shell execution on the runner, potentially exposing runner tokens and secrets including DISCORD_WEBHOOK_URL_ISSUE. Together, the developments underscore how untrusted repository input in CI workflows can quickly become credential exposure and downstream supply-chain compromise.