CVE-2026-120639
Published:November 03, 2026
Updated:November 04, 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.
Affected Packages
https://github.com/leejo/CGI.pm.git (GITHUB):
Affected version(s) =initial-import <v5.01 || >=release-2-28 <v5.01 || >=release-1_62 <v5.01 || >=release-2_751 <v5.01 || >=release-3_01 <v5.01 || =version-3_23 <v5.01 || >=v3.51 <v5.01 || >=v4.00 <v5.01Fix Suggestion:
Update to version v5.01Related Resources (8)
Do you need more information?
Contact UsCVSS v4
Base Score:
5.3
Attack Vector
NETWORK
Attack Complexity
LOW
Attack Requirements
NONE
Privileges Required
NONE
User Interaction
PASSIVE
Vulnerable System Confidentiality
LOW
Vulnerable System Integrity
LOW
Vulnerable System Availability
NONE
Subsequent System Confidentiality
LOW
Subsequent System Integrity
LOW
Subsequent System Availability
NONE
CVSS v3
Base Score:
6.1
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
REQUIRED
Scope
CHANGED
Confidentiality
LOW
Integrity
LOW
Availability
NONE
Weakness Type (CWE)
Improper Neutralization of CRLF Sequences in HTTP Headers
EPSS
Base Score:
0.23