CVE-2026-58058: Nmap

Medium severity, CVSS 6.5. EPSS: 1.5% chance of exploitation in the next 30 days.

Nmap through 7.99 does not keep the IPv6 extension-header walk within the captured packet in ipv6_get_data_primitive (libnetutil/netutil.cc), so the pointer advances past the buffer and the remaining-length computation underflows to a large value. A scanned target or on-path attacker returning a crafted IPv6 response with a truncated extension header can trigger out-of-bounds reads and a crash during raw IPv6 scans.

Affected products

• Nmap Nmap: up to and including 7.99

Published 2026-06-28. Last modified 2026-06-30.