CVE-2026-42004

EUVD-2026-39351
An attacker can send a crafted EDNS OPT record that will be ignored by DNSdist’s filtering rules, but will be rewritten as a valid OPT record when EDNS Client Subnet is inserted, causing the backend to see the EDNS option(s) that DNSdist did not filter.
ProviderTypeBase ScoreAtk. VectorAtk. ComplexityPriv. RequiredVector
OXCNA
3.7 LOW
NETWORK
HIGH
NONE
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N
Base Score
CVSS 3.x
EPSS Score
Percentile: 5.2%
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