CVE Catalog

CVE-2026-87081

HighCVSS 7.5
Published: Updated: Translated: NVD NIST

Exploitation Probability (EPSS)

Low risk
0.35%

29th percentile - higher than 29% of all known CVEs

Summary

Net::IDN::UTS46 versions before 2.590 for Perl allow CPU exhaustion via quadratic punycode encoding of overlong labels before the length check in to_ascii. Labels with many distinct non-ASCII characters cause quadratic CPU cost. All ASCII conversions in the distribution are affected.

Risk Assessment

An attacker can send a long label to exhaust CPU, causing slowdown or denial of service in domain name processing services.

Recommendation

Update Net::IDN::UTS46 to version 2.590 or later. Consider limiting label length before conversion.

Related vulnerabilities

Original NVD description (English source)

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. to_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.

Vulnerability data from NVD (NIST) · CISA KEV · EPSS