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ALPINE-CVE-2026-42955

ALPINE-CVE-2026-42955

This page contains facts from public vulnerability sources. Check the original advisory before updating.

In NLnet Labs Unbound 1.16.2 up to and including 1.25.1, a similar vulnerability as with CVE-2026-40622 in the 'ghost domain names' family of attacks was found in Unbound that could extend the ghost domain window by up to one cached TTL configured value for A/AAAA glue records. Similar to other 'ghost domain names' attacks, an adversary needs to control a (ghost) zone and be able to query a vulnerable Unbound. A single client A/AAAA query can cause Unbound to overwrite the cached expired parent-side glue rrset and essentially extend the ghost domain window by up to one cached TTL configured value ('cache-max-ttl'). In configurations where 'harden-referral-path: yes' is used (non-default configuration), no client query is required since Unbound implicitly performs that query. This is a variant of CVE-2026-40622 which only addressed the NS query.

CVSS 3.7 · Low · Fix available

Published
Updated

Stack: system

Affected products and versions

  • unbound Alpine:v3.22

    Affected ranges
    • ECOSYSTEM: ≥ 1.16.2, < 1.25.2-r0

    Update to 1.25.2-r0

  • unbound Alpine:v3.23

    Affected ranges
    • ECOSYSTEM: ≥ 1.16.2, < 1.25.2-r0

    Update to 1.25.2-r0

  • unbound Alpine:v3.24

    Affected ranges
    • ECOSYSTEM: ≥ 1.16.2, < 1.25.2-r0

    Update to 1.25.2-r0

Original sources

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