CVE-2026-58058

MEDIUMPre-NVD 6.56.5—
EchelonGraph scoreHIGH confidence

Score 6.5 from GitHub Security Advisory published 2026-06-28. a secondary CVSS source baseline 6.5; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
Trending — 4 sources updated this weekElevated
6.5
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS: 0%CVSS: 6.5Exploit: NoneExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

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 v3
6.5
EG Score
6.5(high)
EPSS
19.6%
KEV
Not listed

Published

June 28, 2026

Last Modified

June 30, 2026

Advisory Details (4)

Auto-updated Jun 28, 2026
🔬 Proof of concept available. Upstream fix merged — awaiting tagged release. Sources: github_commit.
generic🟡 PoC Available

Nmap - Integer Underflow in IPv6 Extension Header Parsing | Advisories | VulnCheck

https://www.vulncheck.com/advisories/nmap-integer-underflow-in-ipv6-extension-header-parsing
generic

Nmap Change Log

https://nmap.org/changelog.html
github_commit

commit bb6754e76bb1 (nmap/nmap)

Fix landed in nmap/nmap commit bb6754e76bb1 — awaiting tagged release

https://github.com/nmap/nmap/commit/bb6754e76bb1686315008e1aa1c40202a513fb83
generic🟡 PoC Available

exploitarium/nmap-ipv6-extlen-wrap-poc at main · bikini/exploitarium · GitHub

https://github.com/bikini/exploitarium/tree/main/nmap-ipv6-extlen-wrap-poc

Vendor Advisories for CVE-2026-58058(2)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 24× in last 7d / 32× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-07-06 16:27 UTCEPSS rescore
  2. 2026-07-06 16:27 UTCEPSS rescore
  3. 2026-07-06 08:35 UTCEG score recompute
  4. 2026-07-06 08:35 UTCVendor advisory
  5. 2026-07-06 08:34 UTCGHSA enrichment
  6. 2026-07-06 02:23 UTCEPSS rescore
  7. 2026-07-06 02:23 UTCEPSS rescore
  8. 2026-07-05 07:44 UTCEG score recompute
  9. 2026-07-05 07:44 UTCVendor advisory
  10. 2026-07-05 07:43 UTCGHSA enrichment
  11. 2026-07-05 02:31 UTCEPSS rescore
  12. 2026-07-05 02:30 UTCEPSS rescore
  13. 2026-07-04 06:58 UTCEG score recompute
  14. 2026-07-04 06:58 UTCGHSA enrichment
  15. 2026-07-04 06:31 UTCEPSS rescore
  16. 2026-07-04 06:31 UTCEPSS rescore
  17. 2026-07-03 05:53 UTCEG score recompute
  18. 2026-07-03 05:53 UTCGHSA enrichment
  19. 2026-07-02 05:09 UTCEG score recompute
  20. 2026-07-02 05:09 UTCGHSA enrichment
  21. 2026-07-01 15:07 UTCEPSS rescore
  22. 2026-07-01 04:26 UTCEG score recompute
  23. 2026-07-01 04:26 UTCGHSA enrichment
  24. 2026-06-30 23:22 UTCEPSS rescore
  25. 2026-06-30 03:39 UTCEG score recompute
Show 7 more
  1. 2026-06-30 03:38 UTCGHSA enrichment
  2. 2026-06-29 14:06 UTCEPSS rescore
  3. 2026-06-29 02:53 UTCEG score recompute
  4. 2026-06-29 02:53 UTCGHSA enrichment
  5. 2026-06-28 14:07 UTCEPSS rescore
  6. 2026-06-28 02:10 UTCEG score recompute
  7. 2026-06-28 02:09 UTCMITRE cvelistV5first tracked

Frequently asked(5)

What is CVE-2026-58058?
CVE-2026-58058 is a medium vulnerability published on June 28, 2026. Nmap through 7.99 does not keep the IPv6 extension-header walk within the captured packet in ipv6getdata_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…
When was CVE-2026-58058 disclosed?
CVE-2026-58058 was first published in the National Vulnerability Database on June 28, 2026, with the most recent update on June 30, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-58058 actively exploited?
CVE-2026-58058 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 19.6% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-58058?
CVE-2026-58058 has a CVSS v3 base score of 6.5 (NVD).
How do I remediate CVE-2026-58058?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-58058, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

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