CVE-2026-54478lowCWE-290

CVE-2026-54478: falha de baixa gravidade em NLnet Labs Unbound

DNS Cookie bypass when combined with proxy-protocol use

Publicada em

Aviso por e-mail quando ela entrar no KEV, ganhar PoC pública ou subir de nota.

8Vexday Risk Score

Sem sinal de exploração. Nenhum artefato público de exploração conhecido até agora.

ssvc Trackcvss 3.7epss 0.2%
In NLnet Labs Unbound 1.18.0 up to and including 1.25.1, when Unbound listens on a 'proxy-protocol-port' interface with 'answer-cookie: yes', the RFC 9018 server-cookie SipHash is computed over the proxy's wire address instead of the PROXYv2-declared client. One server cookie obtained through a given proxy node therefore validates for every PROXYv2-declared source behind that node. On a UDP+proxy-protocol front, an off-path attacker can harvest one cookie with a single legitimate query, then replay it under any spoofed source and pass DNS Cookie checks that were deployed to defeat this in the first place.
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N
Produtos afetados
NLnet Labs · Unbound