# 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.

- **Severity:** Medium 6.9 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N`)
- **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:** Yes
- **Published:** 11 Aug 2026
- **Updated:** 14 Aug 2026
- **Also known as:** AZL-95529, CLSA-2026-1789630245, CLSA-2026-1790157825, DEBIAN-CVE-2026-72712, ECHO-6a0e-ede1-c771, GHSA-7j7x-fg87-hwwg, MGASA-2026-0433, OESA-2026-3679, OESA-2026-3680, OESA-2026-3681, OESA-2026-3682, OESA-2026-3745, UBUNTU-CVE-2026-72712

## 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 (Loop with Unreachable Exit Condition)

## Which versions are affected by CVE-2026-72712?


## How do I fix CVE-2026-72712?

Apply the vendor's patch.

## Is CVE-2026-72712 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-72712 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-72712 and fix it if it is affected.

What it is: 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.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-72712 exists.

Affected product: Nmap. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-72712/ (Markdown: https://insights.sbomify.com/CVE-2026-72712/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-72712
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-72712
- OSV: https://osv.dev/vulnerability/CVE-2026-72712

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-72712/
Summaries are generated and may contain mistakes; the official description above is the record.