CVE-2026-58058

Nmap - Integer Underflow in IPv6 Extension Header Parsing

Published Jun 28, 2026 CVSS 4.0 · 6.9 Medium EPSS 1.5% KEV · Not listed
Description
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'poc', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
Description 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.
Title Nmap - Integer Underflow in IPv6 Extension Header Parsing
First Time appeared Nmap
Nmap nmap
Weaknesses CWE-191
CPEs cpe:2.3:a:nmap:nmap:*:*:*:*:*:*:*:*
Vendors & Products Nmap
Nmap nmap
References
Metrics cvssV3_1

{'score': 6.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:L'}

cvssV4_0

{'score': 6.9, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:L/SC:N/SI:N/SA:N'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
VulnCheck
Published
Updated
Jun 29, 2026, 2:53 PM
Reserved
Jun 28, 2026, 12:58 AM
Status
Analyzed
Published
Jun 28, 2026, 2:16 AM
Modified
Oct 25, 2026, 5:10 PM
Severity
Moderate
Public date
Jun 28, 2026, 1:32 AM