TYPO3 Core

Releases (v9.5.20, v10.4.6) use 1.15.0 in their composer.lock file, thus zip & tar.gz releases do not seem to be affected.

However, composer-based installations will use the latest version (1.18.0) which leads to mentioned problems on systems having an outdated or missing intl-icu support in their PHP environment.

References¶

• https://github.com/symfony/polyfill-intl-idn/commit/3bff59ea7047e925be6b7f2059d60af31bb46d6a
• https://github.com/guzzle/guzzle/pull/2678/files

Thus, for composer-based installations we'd probably have to "lock" the version to 1.17.1 in composer.json as well.

→ https://github.com/symfony/polyfill/issues/278