Improper Validation of Syntactic Correctness of Input in Net-CIDR-Lite - CVE-2026-40198
Published: July 28, 2026
Vulnerability details
The vulnerability allows a remote attacker to gain access to modify data on the system.
The vulnerability exists due to the application does not validate IPv6 group count, which may allow IP ACL bypass. _pack_ipv6() does not check that uncompressed IPv6 addresses (without ::) have exactly 8 hex groups. Inputs like "abcd", "1:2:3", or "1:2:3:4:5:6:7" are accepted and produce packed values of wrong length (3, 7, or 15 bytes instead of 17). The packed values are used internally for mask and comparison operations. find() and bin_find() use Perl string comparison (lt/gt) on these values, and comparing strings of different lengths gives wrong results. This can cause find() to incorrectly report an address as inside or outside a range. A remote attacker can gain unauthorized access to sensitive information on the system.
Affected software
IBM Qradar SIEM
Fedora
Ubuntu
libnet-cidr-lite-perl (Ubuntu package)
perl-Net-CIDR-Lite
How to mitigate CVE-2026-40198
IBM Qradar SIEM - update to 7.5.0 Update Pack 15 IF05
libnet-cidr-lite-perl (Ubuntu package) - addressed in versions 0.21-1ubuntu0.16.04.1~esm1, 0.21-1ubuntu0.18.04.1~esm1, 0.21-2ubuntu0.1+esm1, 0.22-1ubuntu0.1, 0.22-2ubuntu0.24.04.1, 0.22-2ubuntu0.25.10.1, 0.22-2ubuntu0.26.04.1
perl-Net-CIDR-Lite - addressed in versions 0.23-1.el8, 0.23-1.el10_1, 0.23-1.el10_2, 0.23-1.el10_3, 0.23-1.fc42, 0.23-1.fc43, 0.23-1.fc44
External References
Related Security Bulletins
- Improper Validation of Syntactic Correctness of Input in Net::CIDR::Lite
- Multiple vulnerabilities in IBM QRadar SIEM
- Fedora EPEL 10.2 update for perl-Net-CIDR-Lite
- Fedora EPEL 10.1 update for perl-Net-CIDR-Lite
- Fedora EPEL 8 update for perl-Net-CIDR-Lite
- Fedora EPEL 10.3 update for perl-Net-CIDR-Lite
- Fedora 44 update for perl-Net-CIDR-Lite
- Fedora 42 update for perl-Net-CIDR-Lite
- Fedora 43 update for perl-Net-CIDR-Lite
- Ubuntu update for libnet-cidr-lite-perl