Upstream information
Description
Net::IDN::Punycode::PP versions before 2.590 for Perl decode a truncated label to a name containing a character it never encoded in decode_punycode.The pure-Perl decoder reads one digit at a time with four-argument substr and tests the result with defined to detect the end of the input. substr on an exhausted string returns the empty string rather than undef, so decoding continues past the end. The empty string converts to a digit value below the range, reducing the accumulator, and the decoder derives one extra code point and its position from it. The result is deterministic. The XS backend rejects the same label.
Net::IDN::Punycode uses this backend wherever the XS does not build.
The two backends disagree about what such a label means, so a sender can pick a label that one installation resolves to a name and another rejects.
Other Security Trackers
SUSE information
Overall state of this security issue: Resolved
This issue is currently rated as having critical severity.
| CVSS detail | CNA (CISA-ADP) |
|---|---|
| Base Score | 9.1 |
| Vector | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H |
| Attack Vector | Network |
| Attack Complexity | Low |
| Privileges Required | None |
| User Interaction | None |
| Scope | Unchanged |
| Confidentiality Impact | High |
| Integrity Impact | None |
| Availability Impact | High |
| CVSSv3 Version | 3.1 |
List of released packages
| Product(s) | Fixed package version(s) | References |
|---|---|---|
| openSUSE Tumbleweed |
| Patchnames: openSUSE-Tumbleweed-2026-12468 |
SUSE Timeline for this CVE
CVE page created: Sat Nov 7 12:50:44 2026CVE page last modified: Sat Nov 7 12:50:44 2026