CVE-2026-120639 PUBLISHED

CGI versions before 5.00 for Perl allow HTTP header injection via entity decoding after the newline check in header and unchecked values in multipart_start and do_push

Assigner: CPANSec
Reserved: 02.11.2026 Published: 03.11.2026 Updated: 03.11.2026

CGI versions before 5.00 for Perl allow HTTP header injection via entity decoding after the newline check in header and unchecked values in multipart_start and do_push.

With autoEscape off, header decodes HTML entities in extra header values after its newline check, so an encoded CR or LF reaches the response. multipart_start does not check header values for newlines, and do_push does not check the type it prints in each part.

An application that passes request data into these header values can be made to add headers or split the response.

Product Status

Package Collection https://cpan.org/modules
Package Name CGI
Versions Default: unaffected
  • affected from 0 to 5.00 (excl.)

Solutions

Upgrade to CGI 5.00 or later.

References

Problem Types

  • CWE-113 Improper Neutralization of CRLF Sequences in HTTP Headers ('HTTP Request/Response Splitting') CWE