CVE-2026-19954

Net::Whois::Raw versions before 2.99044 for Perl ship a pwhois command-line tool that queries WHOIS for the wrong domain for unicode domain names. pwhois encodes each non-ASCII label directly using Net::IDN::Punycode and prepends xn--. Apart from lowercasing ASCII and Cyrillic letters, it skips the IDNA mapping and normalization steps, so a label with other uppercase letters, or not in NFC, encodes to a different A-label than its IDNA form. For example, a label of U+00C9 followed by "cole" encodes to "xn--cole-pka" rather than "xn--cole-9oa". The Net::Whois::Raw library modules are not affected.

• https://github.com/regru/Net-Whois-Raw/issues/34
• https://github.com/regru/Net-Whois-Raw/pull/35
• https://metacpan.org/release/NALOBIN/Net-Whois-Raw-2.99044/changes
• https://metacpan.org/release/PJCJ/Net-IDN-Encode-2.590-TRIAL/view/lib/Net/IDN/Punycode.pm#WARNING
• https://security.metacpan.org/patches/N/Net-Whois-Raw/2.99043/CVE-2026-19954-r1.patch
• https://www.rfc-editor.org/rfc/rfc5891#section-5.2
• http://www.openwall.com/lists/oss-security/2026/10/05/9