Net::Whois::Raw pwhois tool queries wrong domain for Unicode names
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- Required
- Attack complexity
- Low
- Impact type
- —
- Confidentiality · integrity · availability
- Low · Low · None
- Fix status
- Fixed
Attack profile from CVSS 3.1 · CISA ADP. Fix status from CNA.
Summary
Net::Whois::Raw versions before 2.99044 for Perl ship a pwhois command line tool. The tool encodes non ASCII domain labels without the IDNA mapping and normalization steps (CWE-176), so some labels become a different A-label and WHOIS is queried for the wrong domain. Exploitation requires user interaction, and the Net::Whois::Raw library modules are not affected.
Written with Claude Haiku 5.5 from the sources below · 2026-10-29
Description from the CNA
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.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| — | Net-Whois-Raw | before 2.99044 | 2.99044 | Patch available | CNA |
- Net-Whois-Raw Vendor— Affected before 2.99044 Fixed in 2.99044 Patch available CNA
Remediation
Update Net-Whois-Raw to version 2.99044, the fixed version.
Written with Claude Haiku 5.5 from the sources below · 2026-10-29
- Fix · CNA Net-Whois-Raw Fixed in 2.99044
Vendor assessments
Timeline
- 2026-10-05 Threatist record created from CVE-2026-19954
- 2026-10-05 Alias added: GHSA-m543-jcgv-fpx5
- 2026-10-06 Affected versions changed · Red Hat
- 2026-10-06 CVSS score added · Red Hat
- 2026-10-06 CVSS score added · CISA ADP
- 2026-10-06 CISA SSVC decision points changed
References
Other 5
- https://metacpan.org/release/NALOBIN/Net-Whois-Raw-2.99044/changes
- https://github.com/regru/Net-Whois-Raw/issues/34
- https://github.com/regru/Net-Whois-Raw/pull/35
- https://metacpan.org/release/PJCJ/Net-IDN-Encode-2.590-TRIAL/view/lib/Net/IDN/Punycode.pm#WARNING
- https://www.rfc-editor.org/rfc/rfc5891#section-5.2
Sources
- CVE-2026-19954 · CVE Program
- CVE-2026-19954 · NVD
- FIRST EPSS
- GHSA-m543-jcgv-fpx5 · GitHub Advisory Database · CC BY 4.0
- CVE-2026-19954 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences