CVE-2026-87082 (GCVE-0-2026-87082)
Vulnerability from cvelistv5
Published
2026-09-22 07:25
Modified
2026-09-22 17:07
CWE
  • CWE-835 - Loop with Unreachable Exit Condition ('Infinite Loop')
  • CWE-1286 - Improper Validation of Syntactic Correctness of Input
Summary
Net::IDN::Punycode versions before 2.590 for Perl hang, crash or return a wrong label via unvalidated malformed UTF-8 in encode_punycode. Neither backend checks that its input is well-formed UTF-8, so a string with the UTF-8 flag set over malformed bytes, as the :utf8 PerlIO layer produces from any malformed input, reaches the encoder unchecked. On perl 5.32 and later the XS backend reports a malformed sequence with a length of `(STRLEN)-1`, so the scan steps back one byte instead of forward and never ends. On earlier perls the XS returns a valid label for a different name. The pure-Perl backend runs a regex over the flagged string. Depending on the bytes, it aborts with SIGBUS on perl 5.28 and later, dies with a panic, or returns a wrong label. The documented conversion functions match the label against Unicode properties first and that match dies on such a string, so only a direct call to encode_punycode reaches the defect. The decoder is not affected. A direct caller encoding attacker-supplied bytes hangs, crashes or gets a label for a name the input never held.
Impacted products
Vendor Product Version
Version: 0   < 2.590
Create a notification for this product.
Show details on NVD website


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