CVE-2026-40209

EUVD-2026-39348
An attacker might be able to cause outgoing TCP connections to backend to be stuck until a timeout occurs instead of being released immediately, by sending IXFR queries. This could be used to cause a denial of service if there is a limit to the number of concurrent connections to this backend, or if the process runs out of file descriptors.
ProviderTypeBase ScoreAtk. VectorAtk. ComplexityPriv. RequiredVector
OXCNA
5.3 MEDIUM
NETWORK
LOW
NONE
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
Base Score
CVSS 3.x
EPSS Score
Percentile: 21.21%
Early Detection
Affected products identified ahead of NVD analysis through intelligence sources.
VendorProductVersionSource
powerdnsdnsdist
1.9.0 ≤
𝑥
< 1.9.15
CNA
powerdnsdnsdist
2.0.0 ≤
𝑥
< 2.0.7
CNA
Debian logo
Debian Releases
Debian Product
Codename
dnsdist
bookworm
vulnerable
bullseye
vulnerable
forky
2.1.0-2
fixed
sid
2.1.1-1
fixed
trixie
1.9.15-0+deb13u1
fixed
trixie (security)
1.9.16-0+deb13u1
fixed
Ubuntu logo
Ubuntu Releases
Ubuntu Product
Codename
dnsdist
bionic
needs-triage
focal
needs-triage
jammy
needs-triage
noble
needs-triage
questing
ignored
resolute
needs-triage
Common Weakness Enumeration
Vulnerability Media Exposure
References
https://www.dnsdist.org/security-advisories/powerdns-advisory-for-dnsdist-2026-09.html