# CVE-2026-46644: php-symfony-polyfill: Symfony Polyfill backports PHP features and provides compatibility layers for extensions and functions

CVE-2026-46644 is fixed in php-symfony-polyfill on 1 platform by DEBIAN-CVE-2026-46644 (version 1.38.1-1), released June 24, 2026. It is not reported as exploited. Patch Radar priority: Routine.

- Web page: https://patchblox.com/security/cve/CVE-2026-46644
- Priority: Routine
- CVSS: n/a
- EPSS: 0.0054
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Jul 14, 2026

## Description

Symfony Polyfill backports PHP features and provides compatibility layers for extensions and functions. From 1.17.1 until 1.38.1, symfony/polyfill-intl-idn accepts xn-- labels whose Punycode payload is empty or decodes to ASCII-only code points because Idn::process() does not enforce the UTS #46 revision 33 requirement that decoded ACE labels contain at least one non-ASCII code point. Originally unequal domain names can be regarded as equal, which can lead to blacklist bypassing, inconsistent URL parsing, and server-side request forgery in applications using the polyfill to canonicalise or compare hostnames. This issue is fixed in version 1.38.1.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | php-symfony-polyfill Debian 14 | 1.38.1-1 | [DEBIAN-CVE-2026-46644](https://patchblox.com/security/data/fix/linux/debian-cve-2026-46644.md) | Jun 24, 2026 |

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Data as of 2026-11-08T06:59:42Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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