Home

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.

PUBLISHED Reserved 2026-05-15 | Published 2026-07-14 | Updated 2026-07-14 | Assigner GitHub_M




MEDIUM: 6.9CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:L/SI:L/SA:N

Problem types

CWE-1289: Improper Validation of Unsafe Equivalence in Input

Product status

>= 1.17.1, < 1.38.1
affected

>= 1.17.1, < 1.38.1
affected

References

github.com/...lyfill/security/advisories/GHSA-2xf4-cg6j-vhgq

github.com/...ommit/1be936e2491ccebe152bd736dfc91eb1422c8bec

github.com/symfony/polyfill/releases/tag/v1.38.1

cve.org (CVE-2026-46644)

nvd.nist.gov (CVE-2026-46644)

Download JSON