js-yaml

5.5.0 · 15 Oct 2026MIT322.7M / weekRepository Homepage npm Atom feed

Same major only

1 release in betweennotes for 0

Other targets from 3.15.2Latest5.5.0

4.0.0 has no release note on GitHub or in the repository's changelog, so its breaking changes are missing from the counts below.

?
changes to make: 0
advisories fixed: ?
new: ?
fixes

Counted from 0 of 1 release notes. Advisories are counted from the advisory database, in full.

Security

5 advisories still affect 4.0.0

js-yaml has prototype pollution in merge (<<)moderate · GHSA-mh29-5h37-fv8m
js-yaml: maxTotalMergeKeys does not limit CPU use for empty merge sourceshigh · GHSA-2883-xcg3-v3hh
js-yaml: YAML merge-key chains can force quadratic CPU consumptionhigh · GHSA-52cp-r559-cp3m

Upgrading to 4.3.2 clears them.

Upgrade to 4.0.0

npm install js-yaml@4.0.0

What 4.0.0 needs

Reading 4.0.0's manifest…

Check against your package.json

Which of your other dependencies stand in the way of 4.0.0. Read once, not stored.

After upgrading

Run the type checker, the linter and the tests.
Build, and look for new deprecation warnings.
Update peer dependencies the new version asks for.
5 advisories still affect 4.0.0.