CVE-2026-46644

published 2026-07-14

CVE-2026-46644: 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…

Priority P3 41 medium 6.9 CVSS 4.0

AV N AC L AT N PR N UI N VC N VI L VA N SC L SI L SA N E X CR X IR X AR X MAV X MAC X MAT X MPR X MUI X MVC X MVI X MVA X MSC X MSI X MSA X S X AU X R X V X RE X U X

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.

Affected

4 ranges

Vendor	Product	Version range	Fixed in
symfony	polyfill	—	—
symfony	polyfill	>= 1.17.1 < 1.38.1	1.38.1
symfony	polyfill-intl-idn	—	—
symfony	polyfill-intl-idn	>= 1.17.1 < 1.38.1	1.38.1

CVSS provenance

nvd v4.0 6.9 MEDIUM CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:L/SI:L/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

ghsa 5.1 MEDIUM

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CWE-1289