Fork an abandoned dependency only when three things are true at once: the library is load-bearing in your product, no maintained alternative can replace it within a sprint or two, and you are prepared to own its security patches for years rather than weeks. In every other case, patching in place, vendoring the code you actually use, or migrating to an alternative is cheaper. A fork looks like a one-time action, but it is a maintenance commitment in disguise, and most teams underestimate that commitment badly.
How do you know a dependency is actually abandoned?
Abandonment is a pattern, not a single signal. Before you make any decision, look for several of these together:
- No releases or meaningful commits for 18 to 24 months while open issues keep accumulating
- Security reports sitting unanswered in the issue tracker (search the repo for "CVE" and "security")
- The repository is archived, or the maintainer has publicly said they have moved on
- CI is broken against current runtimes, such as the latest Node.js or Python LTS, with no reaction
- Outside pull requests going unreviewed for months, including trivial fixes
Be careful to distinguish abandoned from finished. A small, stable library that parses semver strings or pads text may simply be done: no open bugs, no security reports, nothing left to add. Low commit activity alone tells you nothing. The combination of open security issues and silence is what matters.
When should you fork an abandoned dependency?
You should fork an abandoned dependency when a concrete blocker exists and no lighter option resolves it. The three common blockers are: an open vulnerability with no upstream patch in any release, a hard incompatibility with a runtime or platform you are required to adopt, and a correctness bug in a code path you cannot route around. If none of these apply, you do not have a forking problem, you have a monitoring problem.
There is real precedent for forks done well. In January 2022, the maintainer of colors.js and faker.js intentionally sabotaged both packages, and the community response was a clean fork of faker under new, collective maintainership within days. LibreSSL was forked from OpenSSL in 2014 after Heartbleed exposed how thinly maintained that critical code was. MariaDB forked from MySQL in 2009 when its future governance looked uncertain. In each case the fork existed because a specific, unresolvable blocker existed, and because a group, not a single hero, committed to maintaining it.
The inverse lesson comes from event-stream in 2018: the original maintainer handed the package to a volunteer he did not know, and that volunteer shipped a backdoor targeting a cryptocurrency wallet. Taking over an abandoned package, or trusting someone else who quietly did, carries its own supply-chain risk. A transparent fork with a new name is often safer than a silent handover.
What does maintaining a fork actually cost?
The recurring cost is security work you did not have before. Once you fork, upstream advisories no longer map cleanly to your artifact. Vulnerability scanners match by package name and version, so a renamed fork silently loses advisory coverage for the inherited code, and a same-named private patch gets flagged for a CVE you already fixed until you publish VEX statements or maintain suppressions. Either way, you now triage every advisory against the original codebase yourself, forever.
On top of that, budget for rebase burden if upstream ever revives, publishing infrastructure with signing and provenance, and a named owning team. Treat the fork as first-party code: it should go through the same static analysis and dynamic testing as everything else you write, because nobody upstream is reviewing it anymore.
What are the alternatives to forking?
Most teams reach for a fork too early. Work down this list first:
- Patch in place. npm
overrides, Yarnresolutions,patch-package, pip constraints files, and MavendependencyManagementlet you pin or hot-patch a transitive dependency without owning the whole codebase. - Vendor the fragment. If you use one function from a 10,000-line library, copy that function (license permitting, with attribution), test it, and delete the dependency.
- Replace it. Abandoned libraries usually have a maintained successor. Migration is a bounded, one-time cost; a fork is unbounded.
- Adopt or fund upstream. Offer co-maintainership publicly, through the project's own channels, or fund the maintainer. Burnout is more common than disappearance.
Good software composition analysis shortens this decision: if the vulnerable function in the abandoned library is not reachable from your code, the honest answer may be "do nothing yet and monitor." Safeguard's SCA tracks maintenance signals and reachability together, which is exactly the evidence this decision needs.
How do you fork responsibly?
If the decision lands on forking, do it in a way the rest of the ecosystem can trust:
- Rename clearly, ideally under an organization scope, so nobody confuses your fork with the original or accuses you of typosquatting
- Keep the original license and copyright notices intact; permissive licenses require notice retention and copyleft licenses bind your fork to the same terms
- State your maintenance intent in the README: what you will patch, what you will not
- Upstream your fixes as pull requests anyway, so a revived original can absorb them
- Register the fork in your SBOM and publish security advisories for it, so downstream users and scanners can track it
More patterns for handling unmaintained open source are in our supply chain articles.
FAQ
Is it better to fork or take over the original package?
Taking over preserves the package name, existing users, and advisory matching, but registries transfer names reluctantly after incidents like event-stream, and users have no easy way to audit a quiet ownership change. Fork with a new name when you need speed and verifiable provenance; pursue takeover when you have time and the maintainer's public blessing.
Do vulnerability scanners track forked packages?
Not automatically. Scanners match advisories by package identity, so a renamed fork inherits the code but not the CVE mapping. Publish advisories for your fork, and use VEX statements to declare inherited CVEs fixed or not applicable.
What license issues matter before forking?
Permissive licenses (MIT, Apache 2.0, BSD) allow forks freely as long as notices are retained. Copyleft licenses (GPL, LGPL) require your fork to stay under the same license. Trademarks can restrict the name even when code is free, which is one more reason to rename.
How long do you have to maintain a fork?
As long as the fork ships in production. That is the real test before you start: if you cannot name the team that will still be patching it in three years, choose replacement instead.