Sourced from js-yaml's changelog.

[3.14.2] - 2025-11-15

Security

• Backported v4.1.1 fix to v3

[4.1.1] - 2025-11-12

Security

• Fix prototype pollution issue in yaml merge (<<) operator.

[4.1.0] - 2021-04-15

Added

• Types are now exported as yaml.types.XXX.
• Every type now has options property with original arguments kept as they were (see yaml.types.int.options as an example).

Changed

• Schema.extend() now keeps old type order in case of conflicts (e.g. Schema.extend([ a, b, c ]).extend([ b, a, d ]) is now ordered as abcd instead of cbad).

[4.0.0] - 2021-01-03

Changed

• Check migration guide to see details for all breaking changes.
• Breaking: "unsafe" tags !!js/function, !!js/regexp, !!js/undefined are moved to js-yaml-js-types package.
• Breaking: removed safe* functions. Use load, loadAll, dump instead which are all now safe by default.
• yaml.DEFAULT_SAFE_SCHEMA and yaml.DEFAULT_FULL_SCHEMA are removed, use yaml.DEFAULT_SCHEMA instead.
• yaml.Schema.create(schema, tags) is removed, use schema.extend(tags) instead.
• !!binary now always mapped to Uint8Array on load.
• Reduced nesting of /lib folder.
• Parse numbers according to YAML 1.2 instead of YAML 1.1 (01234 is now decimal, 0o1234 is octal, 1:23 is parsed as string instead of base60).
• dump() no longer quotes :, [, ], (, ) except when necessary, #470, #557.
• Line and column in exceptions are now formatted as (X:Y) instead of at line X, column Y (also present in compact format), #332.
• Code snippet created in exceptions now contains multiple lines with line numbers.
• dump() now serializes undefined as null in collections and removes keys with undefined in mappings, #571.
• dump() with skipInvalid=true now serializes invalid items in collections as null.
• Custom tags starting with ! are now dumped as !tag instead of !<!tag>, #576.
• Custom tags starting with tag:yaml.org,2002: are now shorthanded using !!, #258.

Added

• Added .mjs (es modules) support.
• Added quotingType and forceQuotes options for dumper to configure string literal style, #290, #529.
• Added styles: { '!!null': 'empty' } option for dumper (serializes { foo: null } as "foo: "), #570.

... (truncated)

• 9963d36 3.14.2 released
• 10d3c8e dist rebuild
• 5278870 fix prototype pollution in merge (<<) (#731)
• See full diff in compare view

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