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.

CVSS 3.1

5.4CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N

EPSS

0.2% chance of exploitation in the next 30 days; higher than 13% of CVEs (scores of 2026-10-25)

CWE

CWE-176

Published

2026-10-05

Modified

2026-10-06

Record from

the NVD, synced 2026-10-19

References

• 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

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