CVE-2026-72712 Nmap 7.99 Denial of Service via Zero-Length TCP Option Packet
Remote attackers can crash Nmap by sending crafted packets with zero-length TCP options, causing an infinite loop and out-of-memory condition.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- Available
What is CVE-2026-72712?
CVE-2026-72712 is a medium-severity denial of service vulnerability in Nmap, published on 11 Aug 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Official description
Nmap versions up to and including 7.99 contains a denial of service vulnerability that allows remote attackers to crash the application by sending a crafted packet containing a zero-length TCP option. The malformed packet forces the Packet:parse_options() function in nselib/packet.lua to allocate objects in an infinite loop, causing an out-of-memory condition that results in application crash.
Weakness: CWE-835
Which versions are affected by CVE-2026-72712?
How do I fix CVE-2026-72712?
Apply the vendor's patch.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2026-72712 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-72712 exists.
Sources
Also known as AZL-95529, CLSA-2026-1789630245, CLSA-2026-1790157825, DEBIAN-CVE-2026-72712, ECHO-6a0e-ede1-c771, GHSA-7j7x-fg87-hwwg and 7 more.