9.1

CVE-2026-18664

Wrong interpretation of ACL ranges

When ranges are used for access control (i.e. of the form 1.2.3.4-1.2.3.25), because NSD wrongly compares the IP address with the range on little endian systems, IPs that were meant to be allowed may be denied, and, IPs that were meant to be denied access could be allowed. An IPv4 address is compared with IPv4 ranges as unsigned 32 bit numbers directly with the endianness of the host, but the values to compare are in network byte order (big-endian).  With IPv6 addresses the comparison is done in 4 times a unsigned 32 bit number comparison, again with the endianness of the host where all values are actually in network bye order.
Daten sind bereitgestellt durch National Vulnerability Database (NVD)
Nlnetlabs ≫ Nsd Version >= 3.0.0 < 4.15.1
VulnDex Vulnerability Enrichment
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Zu dieser CVE wurde keine Warnung gefunden.
EPSS Metriken
Typ Quelle Score Percentile
EPSS FIRST.org 0.32% 0.238
CVSS Metriken
Quelle Base Score Exploit Score Impact Score Vector String
NIST 9.1 3.9 5.2
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H
sep@nlnetlabs.nl 8.2 0 0
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:N/VA:N/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/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
CWE-284 Improper Access Control

The product does not restrict or incorrectly restricts access to a resource from an unauthorized actor.

CWE-697 Incorrect Comparison

The product compares two entities in a security-relevant context, but the comparison is incorrect.

https://www.nlnetlabs.nl/downloads/nsd/CVE-2026-18664.txt
Vendor Advisory