GitHub Adds Three-Day Dependabot Cooldown to Block Supply-Chain Attacks

GitHub has introduced a default three-day Dependabot cooldown to help prevent developers from installing newly released malicious packages.

The change follows GitHub’s previously announced npm v12 security protections, which will block several techniques commonly used in software supply-chain attacks.

According to BleepingComputer, Dependabot will now wait 72 hours before proposing an update to a newly released package version.

Dependabot updates will wait 72 hours

Dependabot automatically scans project dependencies and proposes updates when package maintainers publish new versions.

Under the new default policy, Dependabot will wait three days before creating an update proposal. This delay gives package maintainers, security researchers, and automated scanning services more time to identify suspicious releases.

GitHub selected three days as a balance between improving security and keeping software dependencies reasonably current.

Repository maintainers can configure a shorter or longer cooldown period based on their security requirements and update policies.

The cooldown cannot stop every package attack

The Dependabot cooldown mainly protects against malicious releases detected shortly after publication.

It will not stop an attack when a compromised package remains available for longer than the configured delay. Projects could still install the malicious version after the cooldown expires.

GitHub recommends combining the delay with other security measures. Developers should use dependency lockfiles, restricted-scope access tokens, and tightly controlled permissions.

Teams should also disable unnecessary package installation scripts in continuous integration environments. Attackers often abuse installation scripts to execute malicious code during builds or deployments.

PyPI restricts changes to older releases

PyPI is introducing another measure intended to reduce package supply-chain risks.

The Python package repository will reject new files added to a release more than 14 days after its original publication date.

Previously, an attacker who compromised a developer account or publishing workflow could potentially add a malicious file to an older release. Developers may trust these releases because they have existed for months or years without known problems.

The new restriction prevents changes after the two-week window, reducing the risk of release poisoning.

Package repositories strengthen supply-chain security

The new protections follow several high-profile attacks across software development ecosystems, including the TanStack supply-chain incident and the Mastra AI npm supply-chain attack.

These campaigns showed how compromised accounts, malicious package versions, and automated dependency updates can expose large numbers of downstream projects.

GitHub’s Dependabot cooldown and PyPI’s release restrictions will not eliminate supply-chain attacks. However, both measures give developers and security teams more time to detect malicious activity before compromised code reaches production systems.