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CVE-2026-54478 on CTRL-OS 26.05

Aliases: CVE-2026-54478

Packages: unbound

Status: In Progress

Advisory Information

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.

Updates

2026-07-27 19:41 CEST

Metadata changes:

  • Status for package unbound: “In Progress” (6adb4107d901bc4e75e7e4659d2eccdaebe38c21)

2026-07-23 23:53 CEST

Metadata changes:

  • Status for package unbound: “Plausible”

2026-07-23 23:53 CEST

Metadata changes:

  • Status for package unbound: “New”