CVE-2026-54478
CVE-2026-54478: 1 tracked advisory record across Red Hat. Compare source-reported impact, fixes and remediation.
Compare the source-linked records below. Ratings and product/version details belong to each advisory; they are not a single CVE-wide score or proof that every listed product is affected. How VulniPulse collects and checks evidence.
Vendor advisory comparison
Red Hat
1 advisory- Advisory severityLow3.7
Low [CVE-2026-54478] DNS Cookie security bypass via incorrect server cookie calculation
CVE-2026-54478Source published Source updated
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. A flaw was found in Unbound. When Unbound is configured to listen on a proxy-protocol port with DNS cookies enabled, it incorrectly computes the server cookie using the proxy's network…
- Affected products in this advisory
- Red Hat Hardened Images
- Red Hat Enterprise Linux 10
- Red Hat Enterprise Linux 9
- Red Hat OpenShift Container Platform 4
1 more entries in the full advisory.
- Source-reported affected versions
- 1.18.0
- 1.25.1
- Source-reported fixed versions
- unbound-main-1.25.2-0.1.hum1
- RHSA-2026:43588
- Mitigation guidance
- To mitigate this issue, avoid enabling `answer-cookie: yes` when Unbound is configured to listen on a `proxy-protocol-port`. If the `proxy-protocol-port` is essential, consider disabling DNS cookies. If both features are required, ensure the proxy infrastructure is secured and trusted. A restart of the Unbound service is required for configuration changes to take effect.
Android app · Google Play
Monitor future Red Hat CVEs from your phone.
Choose a whole vendor or a precise platform, then receive matching security advisories by phone notification, email, or both. Coverage follows 32 official vendor sources and 160+ reviewed platform categories.