PatchTheCVECVE-2026-19566: Net::CIDR::Set versions before 0.23 for Perl allow memory exhaustion and malformed set ranges via unbounded IP
CVE-2026-19566 is a high-severity flaw (CVSS 7.5) affecting affected software. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.
Net::CIDR::Set versions before 0.23 for Perl allow memory exhaustion and malformed set ranges via unbounded IPv6 prefix lengths. The _encode method accepts any prefix length matching `(0|[1-9][0-9]*)` and passes it to _width2bits(), which builds the mask as `'1' x ($width + 8)`, one character per bit. The _inc() method then unpacks the packed mask into a Perl array of one scalar per byte, so the prefix length alone sets the allocation size: `::/
Why this priority
- High severity
- Remotely exploitable, no login, no user action
A fixed release or distro patch exists.
Timeline
- Published CVE record published
- Updated Record last modified
Exact fixes by distribution
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.
Quick answers
How do I fix CVE-2026-19566?
No fixed release is listed yet. Watch the vendor advisory and apply any mitigation shown on this page.
Is CVE-2026-19566 being exploited?
CVE-2026-19566 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.
What does CVE-2026-19566 affect?
CVE-2026-19566 affects affected software. Severity is high (CVSS 7.5). Net::CIDR::Set versions before 0.23 for Perl allow memory exhaustion and malformed set ranges via unbounded IPv6 prefix lengths. The _encode method accepts any prefix length matching `(0|[1-9][0-9]*)` and passes it to _width2bits(), which
How urgent is CVE-2026-19566?
Priority 44/100. High severity; Remotely exploitable, no login, no user action