Lancet through 2.3.9 contains an SSRF protection bypass vulnerability in netutil.IsInternalIP that misclassifies IPv6 private, link-local, CGNAT and transition addresses as external. Attackers can supply hostnames resolving to these address forms, including NAT64, 6to4 or Teredo embedding internal IPv4, to reach internal services or cloud metadata endpoints.
Fix
Nothing published yet: no patch, vendor advisory or mitigation reference on NVD, no vendor advisory in the News for this CVE, not in CISA's KEV, no fixed package version. BaselineWatch does not guess at one.
Change history 1
- First seenCVSS 6.3NVD modified 2026-10-13 20:17
Affected (CPE criteria) 0
NVD has not attached CPE configurations yet.
References 8
- https://github.com/duke-git/lancet
- https://github.com/duke-git/lancet/blob/v1.4.6/netutil/net.go#L158-L170
- https://github.com/duke-git/lancet/blob/v2.3.9/netutil/net.go#L192-L205
- https://github.com/duke-git/lancet/commit/835111c832939a85416d686a1e99d5fe7060c9b4
- https://github.com/duke-git/lancet/issues/356
- https://github.com/duke-git/lancet/pull/357
- https://www.vulncheck.com/advisories/lancet-through-2.3.9-ssrf-protection-bypass-via-netutil-isinternalip
- https://github.com/duke-git/lancet/issues/356