# What changed in core-js-pure

> 100 changes in core-js-pure 3 from its official release notes, upgrade guides and advisories: 9 breaking, 1 security, 14 new APIs and options. Each one cited. Sources checked 2026-10-19. HTML: https://unstale.sh/npm/core-js-pure/

To see which of these apply to a repository, run `npx @unstale/cli init` in it.

## core-js-pure 3

### Breaking changes

- Non-integer chunkSize or windowSize values now throw TypeError instead of RangeError. (3.50.0) — [release notes](https://github.com/zloirock/core-js/blob/c6a641f74b6f3a54a18fc5426fc945a6795e78ea/CHANGELOG.md#3500---20260805)
- A finite unsafe integer limit now throws RangeError. (3.50.0) — [release notes](https://github.com/zloirock/core-js/blob/c6a641f74b6f3a54a18fc5426fc945a6795e78ea/CHANGELOG.md#3500---20260805)
- A finite unsafe integer limit now throws RangeError. (3.50.0) — [release notes](https://github.com/zloirock/core-js/blob/c6a641f74b6f3a54a18fc5426fc945a6795e78ea/CHANGELOG.md#3500---20260805)
- The array replacer now determines key order, and inherited and non-enumerable properties are no longer ignored. (3.50.0) — [release notes](https://github.com/zloirock/core-js/blob/c6a641f74b6f3a54a18fc5426fc945a6795e78ea/CHANGELOG.md#3500---20260805)
- The pure version is forcibly replaced to ensure it returns properly wrapped Iterator instances; primitive iterators now cause an early error. (3.49.0) — [release notes](https://github.com/zloirock/core-js/blob/c6a641f74b6f3a54a18fc5426fc945a6795e78ea/CHANGELOG.md#3490---20260316)
- The polyfill now throws for unterminated object and array literals and numbers with a decimal point but no fraction. (3.49.0) — [release notes](https://github.com/zloirock/core-js/blob/c6a641f74b6f3a54a18fc5426fc945a6795e78ea/CHANGELOG.md#3490---20260316)
- The polyfill now errors on \u{} and correctly handles some hex escapes at the end of a string. (3.49.0) — [release notes](https://github.com/zloirock/core-js/blob/c6a641f74b6f3a54a18fc5426fc945a6795e78ea/CHANGELOG.md#3490---20260316)
- The polyfill now throws when asked to transfer multiple objects, some of which are non-transferable. (3.49.0) — [release notes](https://github.com/zloirock/core-js/blob/c6a641f74b6f3a54a18fc5426fc945a6795e78ea/CHANGELOG.md#3490---20260316)
- The polyfill now throws when called with only one argument. (3.49.0) — [release notes](https://github.com/zloirock/core-js/blob/c6a641f74b6f3a54a18fc5426fc945a6795e78ea/CHANGELOG.md#3490---20260316)

### Security

- Fixed exposure of buffer mutations in the polyfill. (3.49.0) — [release notes](https://github.com/zloirock/core-js/blob/c6a641f74b6f3a54a18fc5426fc945a6795e78ea/CHANGELOG.md#3490---20260316)

### New APIs and options

- Adds the iterator chunking built-in Iterator.prototype.chunks. (3.50.0) — [release notes](https://github.com/zloirock/core-js/blob/c6a641f74b6f3a54a18fc5426fc945a6795e78ea/CHANGELOG.md#3500---20260805)
- Adds the stage 3 iterator includes built-in. (3.50.0) — [release notes](https://github.com/zloirock/core-js/blob/c6a641f74b6f3a54a18fc5426fc945a6795e78ea/CHANGELOG.md#3500---20260805)
- Adds the stage 3 iterator join built-in. (3.50.0) — [release notes](https://github.com/zloirock/core-js/blob/c6a641f74b6f3a54a18fc5426fc945a6795e78ea/CHANGELOG.md#3500---20260805)
- Adds the iterator chunking built-in Iterator.prototype.windows. (3.50.0) — [release notes](https://github.com/zloirock/core-js/blob/c6a641f74b6f3a54a18fc5426fc945a6795e78ea/CHANGELOG.md#3500---20260805)
- Adds the joint iteration built-in Iterator.zip. (3.50.0) — [release notes](https://github.com/zloirock/core-js/blob/c6a641f74b6f3a54a18fc5426fc945a6795e78ea/CHANGELOG.md#3500---20260805)
- Adds the joint iteration built-in Iterator.zipKeyed. (3.50.0) — [release notes](https://github.com/zloirock/core-js/blob/c6a641f74b6f3a54a18fc5426fc945a6795e78ea/CHANGELOG.md#3500---20260805)
- Adds Promise.allKeyed from the Await dictionary of Promises proposal. (3.50.0) — [release notes](https://github.com/zloirock/core-js/blob/c6a641f74b6f3a54a18fc5426fc945a6795e78ea/CHANGELOG.md#3500---20260805)
- Adds Promise.allSettledKeyed from the Await dictionary of Promises proposal. (3.50.0) — [release notes](https://github.com/zloirock/core-js/blob/c6a641f74b6f3a54a18fc5426fc945a6795e78ea/CHANGELOG.md#3500---20260805)
- Adds namespace entries for the Map upsert features. (3.48.0) — [release notes](https://github.com/zloirock/core-js/blob/c6a641f74b6f3a54a18fc5426fc945a6795e78ea/CHANGELOG.md#3480---20260121)
- Adds the Map upsert method, moved to stable ES. (3.48.0) — [release notes](https://github.com/zloirock/core-js/blob/c6a641f74b6f3a54a18fc5426fc945a6795e78ea/CHANGELOG.md#3480---20260121)
- Adds the Map upsert method, moved to stable ES. (3.48.0) — [release notes](https://github.com/zloirock/core-js/blob/c6a641f74b6f3a54a18fc5426fc945a6795e78ea/CHANGELOG.md#3480---20260121)
- Adds namespace entries for the Map upsert features. (3.48.0) — [release notes](https://github.com/zloirock/core-js/blob/c6a641f74b6f3a54a18fc5426fc945a6795e78ea/CHANGELOG.md#3480---20260121)
- Adds the WeakMap upsert method, moved to stable ES. (3.48.0) — [release notes](https://github.com/zloirock/core-js/blob/c6a641f74b6f3a54a18fc5426fc945a6795e78ea/CHANGELOG.md#3480---20260121)
- Adds the WeakMap upsert method, moved to stable ES. (3.48.0) — [release notes](https://github.com/zloirock/core-js/blob/c6a641f74b6f3a54a18fc5426fc945a6795e78ea/CHANGELOG.md#3480---20260121)

### Performance

- Slightly improves performance on engines with native Array.prototype.fill. (3.50.0) — [release notes](https://github.com/zloirock/core-js/blob/c6a641f74b6f3a54a18fc5426fc945a6795e78ea/CHANGELOG.md#3500---20260805)
- Improves performance of escape. (3.50.0) — [release notes](https://github.com/zloirock/core-js/blob/c6a641f74b6f3a54a18fc5426fc945a6795e78ea/CHANGELOG.md#3500---20260805)
- Slightly improves performance on engines with native Array.prototype.fill. (3.50.0) — [release notes](https://github.com/zloirock/core-js/blob/c6a641f74b6f3a54a18fc5426fc945a6795e78ea/CHANGELOG.md#3500---20260805)
- Improves performance of Uint8Array base64 methods. (3.50.0) — [release notes](https://github.com/zloirock/core-js/blob/c6a641f74b6f3a54a18fc5426fc945a6795e78ea/CHANGELOG.md#3500---20260805)
- The polyfill has improved performance. (3.49.0) — [release notes](https://github.com/zloirock/core-js/blob/c6a641f74b6f3a54a18fc5426fc945a6795e78ea/CHANGELOG.md#3490---20260316)
- The polyfill has improved performance. (3.49.0) — [release notes](https://github.com/zloirock/core-js/blob/c6a641f74b6f3a54a18fc5426fc945a6795e78ea/CHANGELOG.md#3490---20260316)
- The polyfill has improved performance. (3.49.0) — [release notes](https://github.com/zloirock/core-js/blob/c6a641f74b6f3a54a18fc5426fc945a6795e78ea/CHANGELOG.md#3490---20260316)
- The polyfill has improved performance. (3.49.0) — [release notes](https://github.com/zloirock/core-js/blob/c6a641f74b6f3a54a18fc5426fc945a6795e78ea/CHANGELOG.md#3490---20260316)
- The polyfill has improved performance. (3.49.0) — [release notes](https://github.com/zloirock/core-js/blob/c6a641f74b6f3a54a18fc5426fc945a6795e78ea/CHANGELOG.md#3490---20260316)

### Behavior and default changes

- Pure-version methods are now generic and work with polyfilled and native collections. (3.49.0) — [release notes](https://github.com/zloirock/core-js/blob/c6a641f74b6f3a54a18fc5426fc945a6795e78ea/CHANGELOG.md#3490---20260316)

### Fixes and other changes

- Adds the missed MAX_SAFE_INTEGER excess check to the polyfill. (3.50.0) — [release notes](https://github.com/zloirock/core-js/blob/c6a641f74b6f3a54a18fc5426fc945a6795e78ea/CHANGELOG.md#3500---20260805)
- Adds the missed MAX_SAFE_INTEGER excess check to the polyfill. (3.50.0) — [release notes](https://github.com/zloirock/core-js/blob/c6a641f74b6f3a54a18fc5426fc945a6795e78ea/CHANGELOG.md#3500---20260805)
- Improves polyfill accuracy with big and small values. (3.50.0) — [release notes](https://github.com/zloirock/core-js/blob/c6a641f74b6f3a54a18fc5426fc945a6795e78ea/CHANGELOG.md#3500---20260805)
- Improves polyfill accuracy with big and small values. (3.50.0) — [release notes](https://github.com/zloirock/core-js/blob/c6a641f74b6f3a54a18fc5426fc945a6795e78ea/CHANGELOG.md#3500---20260805)
- Adds the missed MAX_SAFE_INTEGER excess check to the polyfill. (3.50.0) — [release notes](https://github.com/zloirock/core-js/blob/c6a641f74b6f3a54a18fc5426fc945a6795e78ea/CHANGELOG.md#3500---20260805)
- Uses PromiseResolve semantics, aligning the polyfill with the specified behavior. (3.50.0) — [release notes](https://github.com/zloirock/core-js/blob/c6a641f74b6f3a54a18fc5426fc945a6795e78ea/CHANGELOG.md#3500---20260805)
- Fixes the conversion order in the polyfill. (3.50.0) — [release notes](https://github.com/zloirock/core-js/blob/c6a641f74b6f3a54a18fc5426fc945a6795e78ea/CHANGELOG.md#3500---20260805)
- Fixes the conversion order in the polyfill. (3.50.0) — [release notes](https://github.com/zloirock/core-js/blob/c6a641f74b6f3a54a18fc5426fc945a6795e78ea/CHANGELOG.md#3500---20260805)
- Fixes a possible crash on some keys. (3.50.0) — [release notes](https://github.com/zloirock/core-js/blob/c6a641f74b6f3a54a18fc5426fc945a6795e78ea/CHANGELOG.md#3500---20260805)
- Parsing is more correct for character sets, percent coding, and related cases. (3.50.0) — [release notes](https://github.com/zloirock/core-js/blob/c6a641f74b6f3a54a18fc5426fc945a6795e78ea/CHANGELOG.md#3500---20260805)
- Opaque paths in the URL polyfill now always roundtrip. (3.50.0) — [release notes](https://github.com/zloirock/core-js/blob/c6a641f74b6f3a54a18fc5426fc945a6795e78ea/CHANGELOG.md#3500---20260805)
- Fixes URL#toJSON when URL#toString is reassigned after core-js is imported. (3.50.0) — [release notes](https://github.com/zloirock/core-js/blob/c6a641f74b6f3a54a18fc5426fc945a6795e78ea/CHANGELOG.md#3500---20260805)
- Fixed iterator closing when array property creation fails. (3.49.0) — [release notes](https://github.com/zloirock/core-js/blob/c6a641f74b6f3a54a18fc5426fc945a6795e78ea/CHANGELOG.md#3490---20260316)
- Fixed argument validation order and missing counter validation at MAX_SAFE_INTEGER. (3.49.0) — [release notes](https://github.com/zloirock/core-js/blob/c6a641f74b6f3a54a18fc5426fc945a6795e78ea/CHANGELOG.md#3490---20260316)
- Fixed an error when the polyfill receives a frozen array. (3.49.0) — [release notes](https://github.com/zloirock/core-js/blob/c6a641f74b6f3a54a18fc5426fc945a6795e78ea/CHANGELOG.md#3490---20260316)
- Fixed the order of argument validation in the polyfill. (3.49.0) — [release notes](https://github.com/zloirock/core-js/blob/c6a641f74b6f3a54a18fc5426fc945a6795e78ea/CHANGELOG.md#3490---20260316)
- Fixed a modern Safari bug involving sparse arrays and fromIndex; modern Safari is marked as unsupported in compatibility data. (3.49.0) — [release notes](https://github.com/zloirock/core-js/blob/c6a641f74b6f3a54a18fc5426fc945a6795e78ea/CHANGELOG.md#3490---20260316)
- Fixed resizable ArrayBuffer transfers when newByteLength exceeds the original maxByteLength. (3.49.0) — [release notes](https://github.com/zloirock/core-js/blob/c6a641f74b6f3a54a18fc5426fc945a6795e78ea/CHANGELOG.md#3490---20260316)
- Fixed iterator closing in the polyfill. (3.49.0) — [release notes](https://github.com/zloirock/core-js/blob/c6a641f74b6f3a54a18fc5426fc945a6795e78ea/CHANGELOG.md#3490---20260316)
- Fixed iterator closing when the underlying iterator next() throws. (3.49.0) — [release notes](https://github.com/zloirock/core-js/blob/c6a641f74b6f3a54a18fc5426fc945a6795e78ea/CHANGELOG.md#3490---20260316)
- Fixed iterator closing with return: null and validation that the return() result is an object. (3.49.0) — [release notes](https://github.com/zloirock/core-js/blob/c6a641f74b6f3a54a18fc5426fc945a6795e78ea/CHANGELOG.md#3490---20260316)
- core-js-builder no longer ignores the obsolete blacklist option; removal is deferred until the next major release. (3.49.0) — [release notes](https://github.com/zloirock/core-js/blob/c6a641f74b6f3a54a18fc5426fc945a6795e78ea/CHANGELOG.md#3490---20260316)
- Compatibility data adds mappings for recent Deno, Electron, Opera for Android, and Oculus Quest Browser releases, and corrects parseInt and parseFloat data. (3.49.0) — [release notes](https://github.com/zloirock/core-js/blob/c6a641f74b6f3a54a18fc5426fc945a6795e78ea/CHANGELOG.md#3490---20260316)
- Fixed the esmodules: intersect option. (3.49.0) — [release notes](https://github.com/zloirock/core-js/blob/c6a641f74b6f3a54a18fc5426fc945a6795e78ea/CHANGELOG.md#3490---20260316)
- Fixed the polyfill for values in the (0, 1) range. (3.49.0) — [release notes](https://github.com/zloirock/core-js/blob/c6a641f74b6f3a54a18fc5426fc945a6795e78ea/CHANGELOG.md#3490---20260316)
- Fixed NaN handling in the polyfill. (3.49.0) — [release notes](https://github.com/zloirock/core-js/blob/c6a641f74b6f3a54a18fc5426fc945a6795e78ea/CHANGELOG.md#3490---20260316)
- Iterator helper polyfills now proxy return() on an exhausted iterator to the underlying iterator. (3.49.0) — [release notes](https://github.com/zloirock/core-js/blob/c6a641f74b6f3a54a18fc5426fc945a6795e78ea/CHANGELOG.md#3490---20260316)
- Fixed another case of a V8 / Chromium bug affecting the polyfill. (3.49.0) — [release notes](https://github.com/zloirock/core-js/blob/c6a641f74b6f3a54a18fc5426fc945a6795e78ea/CHANGELOG.md#3490---20260316)
- Fixed handling of strings as iterables, iterator closing, and validation of next results; the pure version is forcibly replaced to return properly wrapped Iterator instances. (3.49.0) — [release notes](https://github.com/zloirock/core-js/blob/c6a641f74b6f3a54a18fc5426fc945a6795e78ea/CHANGELOG.md#3490---20260316)
- Fixed handling of strings as iterables, iterator closing, and validation of next results; the pure version is forcibly replaced to return properly wrapped Iterator instances. (3.49.0) — [release notes](https://github.com/zloirock/core-js/blob/c6a641f74b6f3a54a18fc5426fc945a6795e78ea/CHANGELOG.md#3490---20260316)
- Improves polyfill accuracy with big and small values. (3.49.0) — [release notes](https://github.com/zloirock/core-js/blob/c6a641f74b6f3a54a18fc5426fc945a6795e78ea/CHANGELOG.md#3500---20260805), [release notes](https://github.com/zloirock/core-js/blob/c6a641f74b6f3a54a18fc5426fc945a6795e78ea/CHANGELOG.md#3490---20260316)
- The polyfill is more accurate for big and small values. (3.49.0) — [release notes](https://github.com/zloirock/core-js/blob/c6a641f74b6f3a54a18fc5426fc945a6795e78ea/CHANGELOG.md#3490---20260316)
- Fixed handling of ending zeroes in the fraction part and added input string validation to the obsolete proposal polyfill. (3.49.0) — [release notes](https://github.com/zloirock/core-js/blob/c6a641f74b6f3a54a18fc5426fc945a6795e78ea/CHANGELOG.md#3490---20260316)
- The polyfill is more accurate for big and small values. (3.49.0) — [release notes](https://github.com/zloirock/core-js/blob/c6a641f74b6f3a54a18fc5426fc945a6795e78ea/CHANGELOG.md#3490---20260316)
- Fixed possible loss of symbol enumerability and the return value in the Symbol polyfill. (3.49.0) — [release notes](https://github.com/zloirock/core-js/blob/c6a641f74b6f3a54a18fc5426fc945a6795e78ea/CHANGELOG.md#3490---20260316)
- Fixed semantics with multiple subscriptions in the obsolete Observable proposal polyfill. (3.49.0) — [release notes](https://github.com/zloirock/core-js/blob/c6a641f74b6f3a54a18fc5426fc945a6795e78ea/CHANGELOG.md#3490---20260316)
- Added the missing reactnative alias to core-js-compat types. (3.49.0) — [release notes](https://github.com/zloirock/core-js/blob/c6a641f74b6f3a54a18fc5426fc945a6795e78ea/CHANGELOG.md#3490---20260316)
- Fixed argument validation order, observable in the error message. (3.49.0) — [release notes](https://github.com/zloirock/core-js/blob/c6a641f74b6f3a54a18fc5426fc945a6795e78ea/CHANGELOG.md#3490---20260316)
- The polyfill now throws for malformed descriptors. (3.49.0) — [release notes](https://github.com/zloirock/core-js/blob/c6a641f74b6f3a54a18fc5426fc945a6795e78ea/CHANGELOG.md#3490---20260316)
- Fixed repeated ToPropertyKey conversion. (3.49.0) — [release notes](https://github.com/zloirock/core-js/blob/c6a641f74b6f3a54a18fc5426fc945a6795e78ea/CHANGELOG.md#3490---20260316)
- Fixed repeated ToPropertyKey conversion; Reflect.set also received fixes for descriptors and non-extensible receivers. (3.49.0) — [release notes](https://github.com/zloirock/core-js/blob/c6a641f74b6f3a54a18fc5426fc945a6795e78ea/CHANGELOG.md#3490---20260316)
- Fixed repeated ToPropertyKey conversion, descriptor handling, and cases involving non-extensible receivers. (3.49.0) — [release notes](https://github.com/zloirock/core-js/blob/c6a641f74b6f3a54a18fc5426fc945a6795e78ea/CHANGELOG.md#3490---20260316)
- Fixed handling of empty groups in the polyfills. (3.49.0) — [release notes](https://github.com/zloirock/core-js/blob/c6a641f74b6f3a54a18fc5426fc945a6795e78ea/CHANGELOG.md#3490---20260316)
- Fixed named backreferences and cases involving other group types and dotAll in the NCG polyfill. (3.49.0) — [release notes](https://github.com/zloirock/core-js/blob/c6a641f74b6f3a54a18fc5426fc945a6795e78ea/CHANGELOG.md#3490---20260316)
- Fixed alternation, line terminators in multiline mode, and input slicing on result objects. (3.49.0) — [release notes](https://github.com/zloirock/core-js/blob/c6a641f74b6f3a54a18fc5426fc945a6795e78ea/CHANGELOG.md#3490---20260316)
- Updated the polyfill to the final spec behavior for cases where this is updated. (3.49.0) — [release notes](https://github.com/zloirock/core-js/blob/c6a641f74b6f3a54a18fc5426fc945a6795e78ea/CHANGELOG.md#3490---20260316)
- Fixed iterator closing in the polyfill. (3.49.0) — [release notes](https://github.com/zloirock/core-js/blob/c6a641f74b6f3a54a18fc5426fc945a6795e78ea/CHANGELOG.md#3490---20260316)
- Fixed iterator closing in the polyfill. (3.49.0) — [release notes](https://github.com/zloirock/core-js/blob/c6a641f74b6f3a54a18fc5426fc945a6795e78ea/CHANGELOG.md#3490---20260316)
- Fixed the order of argument validation in the polyfill. (3.49.0) — [release notes](https://github.com/zloirock/core-js/blob/c6a641f74b6f3a54a18fc5426fc945a6795e78ea/CHANGELOG.md#3490---20260316)
- Polyfills add support for s, d, and v flags when modern engines have bugs in these string methods. (3.49.0) — [release notes](https://github.com/zloirock/core-js/blob/c6a641f74b6f3a54a18fc5426fc945a6795e78ea/CHANGELOG.md#3490---20260316)
- Polyfills add support for s, d, and v flags when modern engines have bugs in these string methods. (3.49.0) — [release notes](https://github.com/zloirock/core-js/blob/c6a641f74b6f3a54a18fc5426fc945a6795e78ea/CHANGELOG.md#3490---20260316)
- Fixed the order of argument validation in the polyfill. (3.49.0) — [release notes](https://github.com/zloirock/core-js/blob/c6a641f74b6f3a54a18fc5426fc945a6795e78ea/CHANGELOG.md#3490---20260316)
- Fixed the order of argument validation in the polyfill. (3.49.0) — [release notes](https://github.com/zloirock/core-js/blob/c6a641f74b6f3a54a18fc5426fc945a6795e78ea/CHANGELOG.md#3490---20260316)
- Fixed the polyfill for counters exceeding 2 ** 32. (3.49.0) — [release notes](https://github.com/zloirock/core-js/blob/c6a641f74b6f3a54a18fc5426fc945a6795e78ea/CHANGELOG.md#3490---20260316)
- Fixed the sticky-mode polyfill; additional flag support is applied when modern engines have bugs in related string methods. (3.49.0) — [release notes](https://github.com/zloirock/core-js/blob/c6a641f74b6f3a54a18fc5426fc945a6795e78ea/CHANGELOG.md#3490---20260316)
- Polyfills add support for s, d, and v flags when modern engines have bugs in these string methods. (3.49.0) — [release notes](https://github.com/zloirock/core-js/blob/c6a641f74b6f3a54a18fc5426fc945a6795e78ea/CHANGELOG.md#3490---20260316)
- Fixed the order of argument validation in the polyfill. (3.49.0) — [release notes](https://github.com/zloirock/core-js/blob/c6a641f74b6f3a54a18fc5426fc945a6795e78ea/CHANGELOG.md#3490---20260316)
- Fixed some cases of Infinity handling in the polyfill. (3.49.0) — [release notes](https://github.com/zloirock/core-js/blob/c6a641f74b6f3a54a18fc5426fc945a6795e78ea/CHANGELOG.md#3490---20260316)
- The polyfill wraps Symbol.for to correctly handle empty string descriptions. (3.49.0) — [release notes](https://github.com/zloirock/core-js/blob/c6a641f74b6f3a54a18fc5426fc945a6795e78ea/CHANGELOG.md#3490---20260316)
- The polyfills now throw when passed an ArrayBuffer and a negative length. (3.49.0) — [release notes](https://github.com/zloirock/core-js/blob/c6a641f74b6f3a54a18fc5426fc945a6795e78ea/CHANGELOG.md#3490---20260316)
- Fixed the order of argument validation in the polyfill. (3.49.0) — [release notes](https://github.com/zloirock/core-js/blob/c6a641f74b6f3a54a18fc5426fc945a6795e78ea/CHANGELOG.md#3490---20260316)
- Fixed URL polyfill parsing and serialization for hosts, schemes, paths, percent encoding, file URLs, and blob origins. (3.49.0) — [release notes](https://github.com/zloirock/core-js/blob/c6a641f74b6f3a54a18fc5426fc945a6795e78ea/CHANGELOG.md#3490---20260316)
- Fixed UTF-8 decoding and invalid continuation-byte handling in the polyfill. (3.49.0) — [release notes](https://github.com/zloirock/core-js/blob/c6a641f74b6f3a54a18fc5426fc945a6795e78ea/CHANGELOG.md#3490---20260316)
- Fixed deletion with duplicate key-value pairs and prevented unnecessary entry removal when the second argument is used. (3.49.0) — [release notes](https://github.com/zloirock/core-js/blob/c6a641f74b6f3a54a18fc5426fc945a6795e78ea/CHANGELOG.md#3490---20260316)
- Adds workarounds for a Safari before 13 bug that silently ignores non-writable array length. (3.48.0) — [release notes](https://github.com/zloirock/core-js/blob/c6a641f74b6f3a54a18fc5426fc945a6795e78ea/CHANGELOG.md#3480---20260121)
- Includes a minor fix and optimization in the constructor polyfill for NCG and dotAll. (3.48.0) — [release notes](https://github.com/zloirock/core-js/blob/c6a641f74b6f3a54a18fc5426fc945a6795e78ea/CHANGELOG.md#3480---20260121)