CVE-2026-58058
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.
Does this matter?
A public exploit is published in Exploit-DB, so the technical barrier is gone even though the severity is medium and EPSS is 1.5%. Treat it as high on anything reachable from the internet.
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.
- CVSS 4.0
- 6.9 MEDIUMCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M
- EPSS
- 1.45% probability · 73th percentile
- Public exploits
- 1 in Exploit-DB · first 17 August 2026
- CISA KEV
- Not listed
- Weakness
- CWE-191
- Affected
- nmap/nmap
- Source
- disclosure@vulncheck.com
EPSS 1.5% since 26 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
Public exploits (1)
Entries in Exploit-DB that cite this CVE. Links go to the Exploit-DB page and to the file in the public repository; nothing is hosted here. A verified tick means the Exploit-DB team confirmed the exploit works against the stated version.
References
- https://github.com/bikini/exploitarium/tree/main/nmap-ipv6-extlen-wrap-pocBroken Link
- https://github.com/nmap/nmap/commit/bb6754e76bb1686315008e1aa1c40202a513fb83Patch
- https://nmap.org/changelog.htmlPatch, Release Notes
- https://www.vulncheck.com/advisories/nmap-integer-underflow-in-ipv6-extension-header-parsingPatch, Third Party Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.