{"id":"CVE-2026-87081","title":"Net::IDN::UTS46 versions before 2.590 for Perl allow CPU exhaustion via quadratic punycode encoding of an overlong label before the length check in to_ascii.\n\nto_ascii punycode encodes each label and only then applies the 63-byte DNS lim…","summary":"Net::IDN::UTS46 versions before 2.590 for Perl allow CPU exhaustion via quadratic punycode encoding of an overlong label before the length check in to_ascii.\n\nto_ascii punycode encodes each label and only then applies the 63-byte DNS lim…","severity":"high","cvss":7.5,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","cwe":["CWE-407"],"product":"Net-IDN-Encode","affected":["Net-IDN-Encode < 2.590"],"published":"2026-09-22","updated":"2026-09-22","sourceUpdated":"2026-09-22T19:07:00.983","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-87081","references":[{"url":"https://github.com/robrwo/Net-IDN-Encode/commit/5ac3315131264670efcd3a29857b651506dfee8e.patch","label":"9b29abf9-4ab0-4765-b253-1875cd9b441e"},{"url":"https://github.com/robrwo/Net-IDN-Encode/commit/ea34f812d7dc67f3b211f4d92e74c6a7e24d764a.patch","label":"9b29abf9-4ab0-4765-b253-1875cd9b441e"},{"url":"https://metacpan.org/release/PJCJ/Net-IDN-Encode-2.590-TRIAL/changes","label":"9b29abf9-4ab0-4765-b253-1875cd9b441e"},{"url":"http://www.openwall.com/lists/oss-security/2026/09/22/16","label":"af854a3a-2127-422b-91ae-364da2661108"}],"tags":["nvd","cve.org"],"ssvc":{"exploitation":"none","automatable":"yes","technicalImpact":"partial","timestamp":"2026-09-22T15:18:17.110980Z"},"ingestedAt":"2026-09-22T08:00:27.698Z","epss":0.0063,"epssPercentile":0.47958,"slug":"CVE-2026-87081","body":"## Overview\n\nNet::IDN::UTS46 versions before 2.590 for Perl allow CPU exhaustion via quadratic punycode encoding of an overlong label before the length check in to_ascii.\n\nto_ascii punycode encodes each label and only then applies the 63-byte DNS limit. encode_punycode in both backends follows the sample implementation in RFC 3492, whose outer loop runs once per distinct non-ASCII code point and scans the whole input each round, so a label of distinct non-ASCII characters costs the square of its length before the limit rejects it. Every ASCII conversion in the distribution, including domain_to_ascii and email_to_ascii, goes through to_ascii.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"twilight","depthScore":41,"depthScoreParts":{"impact":41.3,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[{"seq":209161,"id":"CVE-2026-87081","ts":1790093216719,"field":"cvss","old":null,"new":"7.5"},{"seq":209160,"id":"CVE-2026-87081","ts":1790093216719,"field":"severity","old":"none","new":"high"}]}