CVE-2026-123578: medium-severity vulnerability in hickory-dns
Hickory DNS 0.26.0 before 0.26.2 Response Validation Bypass via QDCOUNT=0
Published
E-mail alert when it lands in KEV, gets a public PoC or its score goes up.
13Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 6.3epss 0.3%
Hickory DNS hickory-net 0.26.0 before 0.26.2 and hickory-proto 0.25.0 through 0.25.2 skip the check that a UDP response's question section matches the query when the response has an empty question section (QDCOUNT=0), and also skip the case-randomization check. Remote attackers able to inject spoofed UDP responses can send QDCOUNT=0 responses to bypass these checks, weakening defenses against DNS spoofing.
CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N
Affected products
hickory-dns · hickory-dnsRelated CVEs — hickory-dns
In the same product, most dangerous first.
CVE-2026-123608HIGHHickory DNS hickory-proto 0.3.1 before 0.26.1 CPU Exhaustion via BinEncoder Name CompressionEPSS 0.4%CVE-2026-123606HIGHHickory-DNS Recursor 0.25.0-alpha.3 through 0.25.2 Glueless-NS Referral AmplificationEPSS 0.4%CVE-2026-123577HIGHHickory DNS 0.24.0 before 0.26.2 DoH Unbounded Request Body Denial of ServiceEPSS 0.4%CVE-2026-123576HIGHHickory DNS 0.24.0 through 0.26.1 Memory Exhaustion via DNS-over-QUIC RequestsEPSS 0.4%CVE-2026-123575HIGHHickory DNS before 0.26.2 DoH Memory Exhaustion via Incomplete Request BodiesEPSS 0.4%CVE-2026-123571HIGHHickory DNS from 0.26.0 before 0.26.2 Panic via TSIG RDATA DecodingEPSS 0.4%