CVE-2026-12490: nlnet labs nsd Improper Access Control
Vulnerability summary
CVE-2026-12490 is a high (CVSS 8.2) Improper Access Control vulnerability in nlnet labs nsd. EPSS estimates a 0.22% chance of exploitation in the next 30 days, higher than 11.3% of scored vulnerabilities.
Advisory lineage
Upstream 0 · Downstream 2 · Related 3Timeline
- 25-06-2026PublishedVulnerability first disclosed.
- 25-06-2026Last modifiedVulnerability information updated.
Description
When a provide-xfr is given with a tls-auth-name, a secondary requesting a transfer should provide a client certificate with that name. However, no client certificate is needed when the request comes in over TLS over the regular tls-port (and not the tls-auth-port) or over over TCP over the regular port, when the other conditions of the provide-xfr rule match.
CVSS metrics
7 scores · 5 sources · 2 versions- OSV · UbuntuEcosystem advisory · calculated8.2HighCVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N
- NVDNIST8.2HighCVSS:4.0/AV:N/AC:H/AT:N/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
- OSV · UbuntuEcosystem advisory · calculated7.5HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
- OSV · DebianEcosystem advisory · calculated7.5HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
- NVDNIST7.5HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
EPSS trend
Probability
0.22%
Chance of exploitation in the next 30 days
Percentile
11%
Versus all other CVEs
30-day change
+0.06 pp
From 0.16% on 19-09-2026
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root cause- CWE-284Improper Access ControlThe product does not restrict or incorrectly restricts access to a resource from an unauthorized actor.
- CWE-306Missing Authentication for Critical FunctionThe product does not perform any authentication for functionality that requires a provable user identity or consumes a significant amount of resources.
Affected systems
Alpine1 product
- nsd< 4.14.3-r0
Debian1 product
- nsdAll versions (No fix recorded) | < 4.14.3-1
Nlnet labs1 product
- nsd≥ 4.10.1, < 4.14.3
Nlnetlabs1 product
- nsd< 4.14.3
Ubuntu1 product
- nsdAll versions (No fix recorded) | < 4.14.0-1ubuntu0.1~esm1
5 vendors · 5 products
