CVE-2026-19401
published 2026-08-26CVE-2026-19401: Any remote client can crash a (debugging/non-release build type) NSD serve child by sending it a special crafted message with a specially tuned number of DNS…
PriorityP342high7.5CVSS 3.1
AVNACLPRNUINSUCNINAH
EPSS
0.36%
29.5th percentile
Any remote client can crash a (debugging/non-release build type) NSD serve child by sending it a special crafted message with a specially tuned number of DNS Cookie options (17 when UDP payload size is 512). By continuously crashing the serve childs, the remote client can severely hamper or, when positioned sufficiently close, deny all DNS service.
Affected
2 ranges
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| nlnet_labs | nsd | >= 4.3.7 < 4.15.1 | 4.15.1 |
| nlnetlabs | nsd | >= 4.3.7 < 4.15.1 | 4.15.1 |
CVSS provenance
nvdv3.17.5HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
nvdv4.08.2HIGHCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/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
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Bugzilla
CVE-2026-19401 nsd: NSD: Remote denial of service via crafted DNS Cookie options
bugzilla·2026-08-26·CVSS 8.2
CVE-2026-19401 [HIGH] CVE-2026-19401 nsd: NSD: Remote denial of service via crafted DNS Cookie options
CVE-2026-19401 nsd: NSD: Remote denial of service via crafted DNS Cookie options
Any remote client can crash a (debugging/non-release build type) NSD serve child by sending it a special crafted message with a specially tuned number of DNS Cookie options (17 when UDP payload size is 512). By continuously crashing the serve childs, the remote client can severely hamper or, when positioned sufficiently close, deny all DNS service.
Bugzilla
CVE-2026-19401 nsd: NSD: Remote denial of service via crafted DNS Cookie options [fedora-all]
bugzilla·2026-08-26·CVSS 8.2
CVE-2026-19401 [HIGH] CVE-2026-19401 nsd: NSD: Remote denial of service via crafted DNS Cookie options [fedora-all]
CVE-2026-19401 nsd: NSD: Remote denial of service via crafted DNS Cookie options [fedora-all]
Disclaimer: Community trackers are created by Red Hat Product Security team on a best effort basis. Package maintainers are required to ascertain if the flaw indeed affects their package, before starting the update process.
Any remote client can crash a (debugging/non-release build type) NSD serve child by sending it a special crafted message with a specially tuned number of DNS Cookie options (17 when UDP payload size is 512). By continuously crashing the serve childs, the remote client can severely hamper or, when positioned sufficiently close, deny all DNS service.
Bugzilla
CVE-2026-19401 nsd: NSD: Remote denial of service via crafted DNS Cookie options [epel-all]
bugzilla·2026-08-26·CVSS 8.2
CVE-2026-19401 [HIGH] CVE-2026-19401 nsd: NSD: Remote denial of service via crafted DNS Cookie options [epel-all]
CVE-2026-19401 nsd: NSD: Remote denial of service via crafted DNS Cookie options [epel-all]
Disclaimer: Community trackers are created by Red Hat Product Security team on a best effort basis. Package maintainers are required to ascertain if the flaw indeed affects their package, before starting the update process.
Any remote client can crash a (debugging/non-release build type) NSD serve child by sending it a special crafted message with a specially tuned number of DNS Cookie options (17 when UDP payload size is 512). By continuously crashing the serve childs, the remote client can severely hamper or, when positioned sufficiently close, deny all DNS service.
2026-08-26
Published