CVE-2026-58058

A flaw was found in Nmap. A remote attacker or a scanned target can send a specially crafted IPv6 response with a truncated extension header. This can lead to an integer underflow, causing out-of-bounds reads and a denial of service (DoS) due to a crash during raw IPv6 scans.

Red Hat rates this flaw as Moderate rather than the AI-assigned Important severity. The Aegis AI-Bot rated UI:N (no user interaction), but nmap is a command-line scanning tool that an operator must manually invoke — initiating a scan is user interaction per the CVSS definition of UI:R. Correcting UI:N to UI:R reduces the CVSS from 7.5 to 6.5, aligning with the upstream CVEORG assessment. The vulnerability requires a scanned target or on-path attacker to return a crafted IPv6 response with a truncated extension header during a raw IPv6 scan.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.

Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.