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Dependency update bot
A tool that opens pull requests when your libraries have newer or safer versions.
What it means
A dependency update bot watches the libraries your project uses and opens a pull request when a newer version exists. Dependabot on GitHub and Renovate are two common examples. Each pull request changes the version number and often adds the release notes, so a person can review one small step.
Most bots do two jobs. Version updates keep everything current on a schedule. Security updates are raised when a known flaw is published for a version you use, so the fix reaches you without anyone having to notice the advisory.
Why it matters
Most software is mostly other people's code, and the flaws in it are published constantly. A team that updates by hand tends to fall behind, and an old version with a known flaw is what attackers look for first. A bot turns upgrading into a steady habit instead of an annual project.
Small frequent updates are also safer than large rare ones. A jump of three years of changes breaks things in ways nobody can trace. The bot supports your vulnerability management and shortens the time between a fix and its use.
How it shows up
You see them as pull requests from a bot account, with the test results next to them. Good practice is to let tests run on every one, group low-risk updates, and review major version changes by hand. Some setups wait a few days after a release before proposing it. Keep the number of open pull requests low enough that a person actually reads them.
Beware of auto-merge without tests. A bad new release, or a hijacked abandoned package, would flow straight into production. Make sure a lockfile records exact versions, and that nobody closes the pull requests unread because there are too many. Review the changelog for anything marked breaking.
Questions people ask
Dependency update bot, answered
Is Dependabot the same as a vulnerability scanner?
Not exactly. Dependabot raises alerts for known flaws and can open fix pull requests. A scanner may look more widely, including at code and containers.
The bot is best at the narrow job of keeping libraries current.
Is it safe to auto-merge bot pull requests?
Only with strong tests and limits, for example patch versions of well-known packages. A bad release would otherwise reach production with no human look.
Many teams auto-merge small updates and review the rest.
Why do we get so many update pull requests?
Each library you use may release often, and each release can produce a pull request. Grouping updates, setting a schedule and limiting open requests all reduce the noise.
Do not let them pile up unread.
Do update bots catch every vulnerable dependency?
No. They rely on public advisory data, so a flaw that is not yet published, or not yet matched to a package, will not trigger an update.
They also do not tell you whether the flaw is reachable in your app.
Will an update bot break our build?
It can, which is why the pull request runs your tests first. A failed test on the bot's branch tells you the update needs work before merging.
Small, frequent updates break less than big ones.
Sources
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Terms that sit next to this one
Dependency vulnerability
A known flaw in a library your application ships.
Patch management
The routine of tracking, testing and rolling out updates across your systems.
Software composition analysis
Inventorying your open-source parts and flagging the ones with known flaws.
Package pinning
Fixing a dependency to one exact version rather than accepting any newer release.
Transitive dependency
A library pulled in by another library you chose, which you still ship.
Updated, but is it reachable?
An update bot fixes known component flaws. Cyberlop tests the running app for what a version bump cannot fix, such as business-logic and cross-account access flaws. Book a pilot on one app.
Or start with a $199 pilot on one application: thirty days, success criteria agreed before day one, credited against the annual if you convert.