{"id":"CVE-2026-46644","summary":"symfony/polyfill-intl-idn accepts xn-- labels whose Punycode payload decodes to ASCII-only: insecure equivalence","details":"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.","aliases":["GHSA-2xf4-cg6j-vhgq"],"modified":"2026-07-17T03:41:48.024000427Z","published":"2026-07-14T20:48:31.771Z","related":["CGA-p924-vcwc-9576"],"database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/46xxx/CVE-2026-46644.json","cna_assigner":"GitHub_M","cwe_ids":["CWE-1289"]},"references":[{"type":"WEB","url":"https://github.com/symfony/polyfill/releases/tag/v1.38.1"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/46xxx/CVE-2026-46644.json"},{"type":"ADVISORY","url":"https://github.com/symfony/polyfill/security/advisories/GHSA-2xf4-cg6j-vhgq"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-46644"},{"type":"FIX","url":"https://github.com/symfony/polyfill/commit/1be936e2491ccebe152bd736dfc91eb1422c8bec"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/symfony/polyfill","events":[{"introduced":"c36c1b42c49a5519b5424733de58412d6f387209"},{"fixed":"1be936e2491ccebe152bd736dfc91eb1422c8bec"},{"fixed":"09e53d15109121636a416310ea0d510bd292c463"}],"database_specific":{"source":["AFFECTED_FIELD","REFERENCES"],"extracted_events":[{"introduced":"1.17.1"},{"fixed":"1.38.1"}]}}],"versions":["v1.38.0","v1.37.0","v1.36.0","v1.35.0","v1.34.0","v1.33.0","v1.32.0","v1.31.0","v1.30.0","v1.29.0","v1.28.0","v1.27.0","v1.26.0","v1.25.0","v1.24.0","v1.23.1","v1.23.0","v1.22.1","v1.22.0","v1.20.0","v1.19.0","v1.18.1","v1.18.0","v1.17.1"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-46644.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V4","score":"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"}]}