CVE-2026-55708

DNS query disclosure via omitted protected zones

Published Jul 22, 2026 · Updated Jul 22, 2026

Information disclosure in NLnet Labs Unbound 1.6.0 through 1.25.1 allows local users to leak protected DNS names via unbound-control. The view_local_data and view_local_datas handlers create a bare local-zone tree for an empty named view without installing the default protected zones. Reachability requires administrative control access, an existing view with no local data, and a mapped client; protected-name queries then escape to public DNS without altering records or service availability.

CVSS severity3.1
Low
EPSS probability0.15%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Information disclosure in NLnet Labs Unbound 1.6.0 through 1.25.1 allows local users to leak protected DNS names via unbound-control. The view_local_data and view_local_datas handlers create a bare local-zone tree for an empty named view without installing the default protected zones. Reachability requires administrative control access, an existing view with no local data, and a mapped client; protected-name queries then escape to public DNS without altering records or service availability.

The record

CVE
CVE-2026-55708
Published
Jul 22, 2026
Updated
Jul 22, 2026
Vendor
NLnet Labs
Product
Unbound
Classifications
CWE-1188
Attack vector
local
Privileges
admin

Timeline

How it unfolded

  1. Jul 22, 2026CVE publishedPublication date reported by the CVE source.
  2. Jul 22, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=1.6.0 <1.25.2

What conditions does exploitation require?

Attack vectorlocal
Required privilegesadmin

What is affected?

NLnet Labs · Unboundversion=1.6.0 <1.25.2

Published CVSS scores

3.1NLnet LabsCVSS:3.1/AV:L/AC:L/PR:H/UI:R/S:U/C:L/I:L/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesadmin
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-1188Initialization of a Resource with an Insecure Default

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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