Nmap 7.99 Denial of Service via Zero-Length TCP Option Packet (CVE-2026-72712) | HOL Guard CVE

Medium · CVSS 6.5CVE-2026-72712

Nmap 7.99 Denial of Service via Zero-Length TCP Option Packet

Answer in brief

CVE-2026-72712 records a Medium severity (CVSS 6.5) vulnerability in Nmap 7.99 Denial of Service via Zero-Length TCP Option Packet. The current sources do not mark it as known exploited. The current feed maps Nmap Project/Nmap (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Aug 11, 2026Updated Aug 14, 2026Source checked Sep 25, 2026First seen by HOL Aug 11, 2026Material review Aug 14, 2026

Upstream Advisory

Key facts

Risk: Medium · CVSS 6.5
Exploitation: Not marked as known exploited
Affected software: 1 mapped package or product
Fix availability: Not reported

Why this deserves its current priority

CVSS is 6.5. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps Nmap Project/Nmap (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
Nmap Project/Nmapgeneric	0	Not reported

Recommended response

Check inventory. Check lockfiles and deployed manifests for Nmap Project/Nmap.
Review the reported fix. Monitor this advisory for an available fix and review any installs of the affected package.

Evidence timeline and material changes

Published upstream
Aug 11, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Aug 14, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Aug 11, 2026

Sources and claim methodology

Upstream source 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.

Quoted source text, attributed separately from HOL analysis.