7.5High
CVE-2026-86287
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.
What this means for your business
- An attacker can use it remotely, over a network, without a login, and without anyone at your company clicking anything.
- FIRST's prediction model gives it a 0.4% chance of attack attempts being seen in the next 30 days, ranking above 31% of all known flaws.
What to do
- 1Ask your IT team or provider whether any of your systems use the affected product.
- 2If you do, follow the vendor's guidance. No patch reference has been published yet.
Not sure if your company is exposed?
Fastnexa’s certified penetration testers can check whether attackers could use this flaw, or others like it, against your websites, apps and network. The full test is free for our first 10 founding clients until 31 December 2026.
Scoring
- CVSS
- 7.5 (v3.1)
- Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H- Weakness
- CWE-1287
- Assigned by
- 9b29abf9-4ab0-4765-b253-1875cd9b441e
Dates
- Published
- 2026-09-07
- Last modified
- 2026-09-08
- Sources
- NVD