Packages

js-yaml

5.5.0 · 15 Oct 2026MIT322.7M / weekRepositoryHomepagenpmAtom feed

Upgrading js-yaml from 5.3.0 to 5.5.0

5 releases in betweenevery note read

Other targets from 5.3.0Clears its advisory5.4.1
2
changes to make
1
advisory fixed
2
new
9
fixes

Before you upgrade

Tick each one off as you go
  • breaking5.4.0
  • breaking5.4.0

Security

Fixes 1 advisory affecting 5.3.0

  • Count empty mappings in merge sequences toward maxTotalMergeKeys to limit CPU usage, #797.

    5.4.1

Release by release

  1. 5.5.0

    15 Oct 20262 fixes
    • fixed

      Correct percent-encoding of shorthand and verbatim tags.

    • fixed

      Reject ,, ], and } at the start of block plain scalars, #801.

  2. 5.4.3

    5 Oct 20261 fix
    • fixed

      Fixed loading a whitespace-only block scalar followed by a less indented line, #802.

  3. 5.4.2

    13 Sep 20261 fix
    • fixed

      forceQuotes no longer quotes non-string scalars, #798.

  4. 5.4.1nothing new or fixed in the note

  5. 5.4.0

    25 Aug 20262 new · 5 fixes
    • new

      Added the scalarStyleRules dumper option to customize string formatting. See Scalar styling for details.

    • new

      Add an explicit document-end marker after keep-chomped block scalars when needed to preserve trailing newlines.

    • fixed

      Accept a byte order mark at the start of each document in a stream, #791.

    • fixed

      Produce valid flow mappings with quoteFlowKeys and flowSkipColonSpace, including alias and property-only keys, #786.

    • fixed

      Preserve empty scalar items when converting block sequences to flow style.

    • fixed

      Do not apply the 1024-character simple-key limit to flow mapping keys.

    • fixed

      Count Unicode code points, rather than UTF-16 code units, for the 1024-character simple-key limit.

4 other lines we could not sort, mostly version bumps

  • Updated argparse to v3.

    5.5.0

  • Updated development dependencies.

    5.5.0

  • Hard-limit merge sequence size to 100.

    5.4.1

  • Reworked scalar style selection. This can change formatting without changing loaded values; in particular, whitespace-only strings are now double-quoted.

    5.4.0