Medium [CVE-2026-72712] Denial of Service via zero-length TCP option packet
This medium-severity Red Hat Linux advisory covers CVE-2026-72712 affecting Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 6, Red Hat Enterprise Linux 7.
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Summary
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. A flaw was found in Nmap.
A remote attacker can exploit this denial of service vulnerability by sending a specially crafted packet that includes a zero-length Transmission Control Protocol (TCP) option. This malformed packet forces the application to enter an infinite loop during packet processing, consuming excessive memory and ultimately causing the Nmap application to crash.
The impact is limited to the availability of the Nmap process itself, typically affecting active network scanning operations rather than persistent services. Red Hat severity: Moderate — CVSS 6.5 (CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H).
Weakness: CWE-835. Affected Red Hat products: Red Hat Enterprise Linux 10; Red Hat Enterprise Linux 6; Red Hat Enterprise Linux 7; Red Hat Enterprise Linux 8; Red Hat Enterprise Linux 9; Red Hat OpenShift Container Platform 4.
Will not fix / out of support: Red Hat Enterprise Linux 6. Red Hat does not currently list a fixing RHSA for this CVE.
Fixed versions
No fixed release is recorded yet. That does not prove no patch exists — confirm against the vendor advisory.
Official advisory · high-confidence parse· fetched 1 hour ago·verify at source
Mitigation checklist
- To mitigate this issue, avoid running Nmap with Network Scripting Engine (NSE) scripts that perform raw packet dissection against untrusted or potentially malicious network targets. This vulnerability is triggered by specially crafted TCP packets when Nmap is actively scanning with such scripts. If Nmap is not required, consider uninstalling the `nmap` package to eliminate the risk.
Official advisory · high-confidence parse· fetched 1 hour ago·verify at source
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