{"id":"CVE-2026-46644","state":"PUBLISHED","title":"symfony/polyfill-intl-idn accepts xn-- labels whose Punycode payload decodes to ASCII-only: insecure equivalence","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.","publishedAt":"2026-07-14T20:48:31.771Z","updatedAt":"2026-07-15T12:52:31.603Z","severity":{"score":6.9,"label":"Medium","version":"4.0","vector":"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","source":"GitHub_M"},"assigner":"GitHub_M","products":["symfony polyfill","symfony polyfill-intl-idn"],"affected":[{"vendor":"symfony","product":"polyfill","versions":[{"version":">= 1.17.1, < 1.38.1","status":"affected"}]},{"vendor":"symfony","product":"polyfill-intl-idn","versions":[{"version":">= 1.17.1, < 1.38.1","status":"affected"}]}],"references":["https://github.com/symfony/polyfill/security/advisories/GHSA-2xf4-cg6j-vhgq","https://github.com/symfony/polyfill/commit/1be936e2491ccebe152bd736dfc91eb1422c8bec","https://github.com/symfony/polyfill/releases/tag/v1.38.1"],"weaknesses":["CWE-1289"],"ingestedAt":"2026-10-29T20:12:07.131Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/46xxx/CVE-2026-46644.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-46644","state":"PUBLISHED","datePublished":"2026-07-14T20:48:31.771Z","dateUpdated":"2026-07-15T12:52:31.603Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2026-05-15T20:11:54.584Z"},"containers":{"cna":{"title":"symfony/polyfill-intl-idn accepts xn-- labels whose Punycode payload decodes to ASCII-only: insecure equivalence","descriptions":[{"lang":"en","value":"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":[{"vendor":"symfony","product":"polyfill","versions":[{"version":">= 1.17.1, < 1.38.1","status":"affected"}]},{"vendor":"symfony","product":"polyfill-intl-idn","versions":[{"version":">= 1.17.1, < 1.38.1","status":"affected"}]}],"references":[{"url":"https://github.com/symfony/polyfill/security/advisories/GHSA-2xf4-cg6j-vhgq","name":"https://github.com/symfony/polyfill/security/advisories/GHSA-2xf4-cg6j-vhgq","tags":["x_refsource_CONFIRM"]},{"url":"https://github.com/symfony/polyfill/commit/1be936e2491ccebe152bd736dfc91eb1422c8bec","name":"https://github.com/symfony/polyfill/commit/1be936e2491ccebe152bd736dfc91eb1422c8bec","tags":["x_refsource_MISC"]},{"url":"https://github.com/symfony/polyfill/releases/tag/v1.38.1","name":"https://github.com/symfony/polyfill/releases/tag/v1.38.1","tags":["x_refsource_MISC"]}],"metrics":[{"cvssV4_0":{"attackVector":"NETWORK","attackComplexity":"LOW","attackRequirements":"NONE","privilegesRequired":"NONE","userInteraction":"NONE","vulnConfidentialityImpact":"NONE","vulnIntegrityImpact":"LOW","vulnAvailabilityImpact":"NONE","subConfidentialityImpact":"LOW","subIntegrityImpact":"LOW","subAvailabilityImpact":"NONE","baseScore":6.9,"baseSeverity":"MEDIUM","vectorString":"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","version":"4.0"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-1289","lang":"en","description":"CWE-1289: Improper Validation of Unsafe Equivalence in Input","type":"CWE"}]}],"providerMetadata":{"shortName":"GitHub_M","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateUpdated":"2026-07-14T20:48:31.771Z"},"source":{"advisory":"GHSA-2xf4-cg6j-vhgq","discovery":"UNKNOWN"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-07-15T12:52:21.173743Z","id":"CVE-2026-46644","options":[{"Exploitation":"none"},{"Automatable":"yes"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-07-15T12:52:31.603Z"}}]}}}