Skip to main content
CVE-2026-77955VulnerabilityPublished Updated

In NLnet Labs Unbound 1.13.2 up to and including 1.26.1, a vulnerability in ZONEMD configured zones (zonemd-check

Affects unboundSource GCVE Database

0
Compare
Authoritative record:CVE-2026-77955· Medium 4.4

Not known to be exploited · CVSS 4.4 Medium.

Data as of 7 Nov 2026, 23:24 UTC

CVSS 3.1 base score
4.4Medium
How severe the flaw is on the 0–10 CVSS scale.
EPSS
0.1% chance of exploitation in 30 days – higher than 6% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:N/I:H/A:N

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 16 Sep 2026

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponized: no evidence on record.

    No public exploit code indexed in Metasploit or Exploit-DB

  4. Exploited in the wild: no evidence on record.

    Not in CISA KEV and no source reports exploitation

  5. Observed by OffSeq Mirage: no evidence on record.

    No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 8 Nov 2026.

What to do

Affected software

ProductAffectedFixed in
Ubuntu 26.10unboundpkg:deb/ubuntu/unbound?arch=source&distro=stonkingOther threatsAffected
  • =1.24.2-1ubuntu2
  • =1.25.1-1ubuntu1
  • =1.25.1-1ubuntu3
Fixed in–
Ubuntu 26.04 LTSunboundpkg:deb/ubuntu/unbound?arch=source&distro=resoluteOther threatsAffected
  • 1.22.0-2ubuntu2 – 1.24.2-1ubuntu2.4
8 affected builds
Fixed in–
Ubuntu 24.04 LTSunboundpkg:deb/ubuntu/unbound?arch=source&distro=nobleOther threatsAffected
  • 1.17.1-2 – 1.19.2-1ubuntu3.12
17 affected builds
Fixed in–
Ubuntu 22.04 LTSunboundpkg:deb/ubuntu/unbound?arch=source&distro=jammyOther threatsAffected
  • 1.13.1-1ubuntu1 – 1.13.1-1ubuntu5.17
18 affected builds
Fixed in–
Ubuntu Pro 20.04 LTSunboundpkg:deb/ubuntu/unbound?arch=source&distro=esm-infra/focalOther threatsAffected
  • 1.9.0-2ubuntu1 – 1.9.4-2ubuntu1.11+esm3
16 affected builds
Fixed in–
Ubuntu Pro 18.04 LTSunboundpkg:deb/ubuntu/unbound?arch=source&distro=esm-infra/bionicOther threatsAffected
  • 1.6.5-1 – 1.6.7-1ubuntu2.6+esm6
16 affected builds
Fixed in–

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

Until a fix is available, administrators should be aware of the risk of tampered zone data persisting on disk and consider monitoring or manual intervention to discard corrupted data if detected.

Description

NLnet Labs Unbound versions 1.13.2 through 1.26.1 have a vulnerability affecting zones configured with ZONEMD (zonemd-check: yes) located below a trust anchor. Due to asynchronous DS/DNSKEY resolution before ZONEMD integrity checks complete, tampered zone contents may be temporarily served or stored on disk. If tampered data is written and the ZONEMD check fails, corrupted data persists on disk and is reloaded on startup until verification succeeds or data is discarded.

References

Community reviews

Loading reviews…