{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-19953","assignerOrgId":"9b29abf9-4ab0-4765-b253-1875cd9b441e","state":"PUBLISHED","assignerShortName":"CPANSec","dateReserved":"2026-08-15T21:13:08.480Z","datePublished":"2026-08-31T17:29:42.929Z","dateUpdated":"2026-09-01T15:16:50.672Z"},"containers":{"cna":{"affected":[{"collectionURL":"https://cpan.org/modules","defaultStatus":"unaffected","modules":["URI"],"packageName":"URI","packageURL":"pkg:cpan/URI","programFiles":["lib/URI/_idna.pm"],"programRoutines":[{"name":"URI::_idna::nameprep"}],"repo":"https://github.com/libwww-perl/URI","versions":[{"lessThan":"5.36","status":"affected","version":"0","versionType":"custom"}]}],"credits":[{"lang":"en","type":"finder","value":"Naseeb Dangi (naseeb0), Nankai University"}],"descriptions":[{"lang":"en","value":"URI versions before 5.36 for Perl encode non-NFC host names to non-standard punycode labels via missing normalization in nameprep.\n\nnameprep lowercases each host label but performs no Unicode normalization. IDNA requires a label to be normalized to Form C before it is encoded (RFC 5891), so a label that is not already in NFC is encoded to a different A-label than its normalized form. A label built from the precomposed Devanagari sequence U+0958 U+093E encodes to xn--72b5c without normalization but to xn--11b2fg after NFC normalization, and xn--72b5c does not round-trip back to the original label.\n\nAny caller that reads host() from a URI built from untrusted input and uses it for a security decision (an allow or deny list, an SSRF filter, deduplication, a cache key) sees the non-standard label, while a client that fetches the same URL resolves the NFC form, so the check and the fetch can disagree about the host."}],"problemTypes":[{"descriptions":[{"cweId":"CWE-1289","description":"CWE-1289 Improper Validation of Unsafe Equivalence in Input","lang":"en","type":"CWE"}]}],"providerMetadata":{"orgId":"9b29abf9-4ab0-4765-b253-1875cd9b441e","shortName":"CPANSec","dateUpdated":"2026-08-31T17:29:42.929Z"},"references":[{"tags":["patch"],"url":"https://github.com/libwww-perl/URI/commit/956619a9e94f86d8d2c529b4e06a3674c54a73e7.patch"},{"tags":["issue-tracking"],"url":"https://github.com/libwww-perl/URI/pull/191"},{"tags":["release-notes"],"url":"https://metacpan.org/release/OALDERS/URI-5.36/changes"},{"tags":["technical-description"],"url":"https://www.rfc-editor.org/rfc/rfc5891#section-5.2"}],"solutions":[{"lang":"en","value":"Upgrade to URI 5.36 or later."}],"source":{"discovery":"UNKNOWN"},"title":"URI versions before 5.36 for Perl encode non-NFC host names to non-standard punycode labels via missing normalization in nameprep","x_generator":{"engine":"cpansec-cna-tool 0.1"}},"adp":[{"title":"CVE Program Container","references":[{"url":"http://www.openwall.com/lists/oss-security/2026/08/31/14"}],"providerMetadata":{"orgId":"af854a3a-2127-422b-91ae-364da2661108","shortName":"CVE","dateUpdated":"2026-08-31T20:07:50.422Z"}},{"metrics":[{"cvssV3_1":{"scope":"UNCHANGED","version":"3.1","baseScore":6.5,"attackVector":"NETWORK","baseSeverity":"MEDIUM","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N","integrityImpact":"LOW","userInteraction":"NONE","attackComplexity":"LOW","availabilityImpact":"NONE","privilegesRequired":"NONE","confidentialityImpact":"LOW"}},{"other":{"type":"ssvc","content":{"timestamp":"2026-09-01T15:16:46.820304Z","id":"CVE-2026-19953","options":[{"Exploitation":"none"},{"Automatable":"yes"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"title":"CISA ADP Vulnrichment","providerMetadata":{"orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","shortName":"CISA-ADP","dateUpdated":"2026-09-01T15:16:50.672Z"}}]}}