CVE-2026-86287 Net::IP::LPM versions before 1.12 for Perl accept malformed prefix lengths
Attackers can bypass IP allow-lists or deny-lists by providing malformed prefix lengths, causing the library to incorrectly accept or block all addresses.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-86287?
CVE-2026-86287 is a high-severity vulnerability, published on 7 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
Net::IP::LPM versions before 1.12 for Perl accept malformed prefix lengths.
Non-numeric and non-ASCII prefix lengths are accepted and treated as 0. Integers over 31 bits are silently truncated. A single malformed mask will poison the lookup table.
The result is that the lookup will silently succeed for every address. An allow-list will allow every address, and a deny-list will block every address.
Weakness: CWE-1287
Which versions are affected by CVE-2026-86287?
How do I fix CVE-2026-86287?
No fix has been published for CVE-2026-86287 yet. Limit exposure of the affected software until one is available.
Is CVE-2026-86287 being exploited?
There is no known exploitation of CVE-2026-86287 in the wild and no public exploit code.
Sources
Also known as GHSA-456r-qjr2-xph9.