CVEDB API

Vulnerabilities

Vulnerable Software

Vulnerability Details CVE-2026-81634

In NLnet Labs Unbound up to and including 1.26.0, a 255 length query name with a large TCP response can lead to a heap buffer overflow during the RRSet canonicalisation routine. This is caused by missing to add the first owner name into the buffer length check. A malicious actor operating a malicious name server or tampering with an incoming response to Unbound (canonicalisation happens before DNSSEC validation), can trigger the vulnerability.

Exploit prediction scoring system (EPSS) score

EPSS Score 0.004

EPSS Ranking 29.4%

CVSS Severity

CVSS v3 Score 7.5

References

https://www.nlnetlabs.nl/downloads/unbound/CVE-2026-81634.txt

Products affected by CVE-2026-81634

Nlnetlabs » Unbound » Version: N/A

cpe:2.3:a:nlnetlabs:unbound:-
Nlnetlabs » Unbound » Version: 0.0

cpe:2.3:a:nlnetlabs:unbound:0.0
Nlnetlabs » Unbound » Version: 0.1

cpe:2.3:a:nlnetlabs:unbound:0.1
Nlnetlabs » Unbound » Version: 0.10

cpe:2.3:a:nlnetlabs:unbound:0.10
Nlnetlabs » Unbound » Version: 0.11

cpe:2.3:a:nlnetlabs:unbound:0.11
Nlnetlabs » Unbound » Version: 0.2

cpe:2.3:a:nlnetlabs:unbound:0.2
Nlnetlabs » Unbound » Version: 0.3

cpe:2.3:a:nlnetlabs:unbound:0.3
Nlnetlabs » Unbound » Version: 0.4

cpe:2.3:a:nlnetlabs:unbound:0.4
Nlnetlabs » Unbound » Version: 0.5

cpe:2.3:a:nlnetlabs:unbound:0.5
Nlnetlabs » Unbound » Version: 0.6

cpe:2.3:a:nlnetlabs:unbound:0.6
Nlnetlabs » Unbound » Version: 0.7

cpe:2.3:a:nlnetlabs:unbound:0.7
Nlnetlabs » Unbound » Version: 0.7.1

cpe:2.3:a:nlnetlabs:unbound:0.7.1
Nlnetlabs » Unbound » Version: 0.7.2

cpe:2.3:a:nlnetlabs:unbound:0.7.2
Nlnetlabs » Unbound » Version: 0.8

cpe:2.3:a:nlnetlabs:unbound:0.8
Nlnetlabs » Unbound » Version: 0.9

cpe:2.3:a:nlnetlabs:unbound:0.9
Nlnetlabs » Unbound » Version: 1.0.0

cpe:2.3:a:nlnetlabs:unbound:1.0.0
Nlnetlabs » Unbound » Version: 1.0.1

cpe:2.3:a:nlnetlabs:unbound:1.0.1
Nlnetlabs » Unbound » Version: 1.0.2

cpe:2.3:a:nlnetlabs:unbound:1.0.2
Nlnetlabs » Unbound » Version: 1.1.0

cpe:2.3:a:nlnetlabs:unbound:1.1.0
Nlnetlabs » Unbound » Version: 1.1.1

cpe:2.3:a:nlnetlabs:unbound:1.1.1
Nlnetlabs » Unbound » Version: 1.10.0

cpe:2.3:a:nlnetlabs:unbound:1.10.0
Nlnetlabs » Unbound » Version: 1.10.1

cpe:2.3:a:nlnetlabs:unbound:1.10.1
Nlnetlabs » Unbound » Version: 1.11.0

cpe:2.3:a:nlnetlabs:unbound:1.11.0
Nlnetlabs » Unbound » Version: 1.12.0

cpe:2.3:a:nlnetlabs:unbound:1.12.0
Nlnetlabs » Unbound » Version: 1.13.0

cpe:2.3:a:nlnetlabs:unbound:1.13.0
Nlnetlabs » Unbound » Version: 1.13.1

cpe:2.3:a:nlnetlabs:unbound:1.13.1
Nlnetlabs » Unbound » Version: 1.13.2

cpe:2.3:a:nlnetlabs:unbound:1.13.2
Nlnetlabs » Unbound » Version: 1.14.0

cpe:2.3:a:nlnetlabs:unbound:1.14.0
Nlnetlabs » Unbound » Version: 1.15.0

cpe:2.3:a:nlnetlabs:unbound:1.15.0
Nlnetlabs » Unbound » Version: 1.16.0

cpe:2.3:a:nlnetlabs:unbound:1.16.0
Nlnetlabs » Unbound » Version: 1.16.1

cpe:2.3:a:nlnetlabs:unbound:1.16.1
Nlnetlabs » Unbound » Version: 1.16.2

cpe:2.3:a:nlnetlabs:unbound:1.16.2
Nlnetlabs » Unbound » Version: 1.16.3

cpe:2.3:a:nlnetlabs:unbound:1.16.3
Nlnetlabs » Unbound » Version: 1.17.0

cpe:2.3:a:nlnetlabs:unbound:1.17.0
Nlnetlabs » Unbound » Version: 1.17.1

cpe:2.3:a:nlnetlabs:unbound:1.17.1
Nlnetlabs » Unbound » Version: 1.18.0

cpe:2.3:a:nlnetlabs:unbound:1.18.0
Nlnetlabs » Unbound » Version: 1.19.0

cpe:2.3:a:nlnetlabs:unbound:1.19.0
Nlnetlabs » Unbound » Version: 1.19.1

cpe:2.3:a:nlnetlabs:unbound:1.19.1
Nlnetlabs » Unbound » Version: 1.19.2

cpe:2.3:a:nlnetlabs:unbound:1.19.2
Nlnetlabs » Unbound » Version: 1.19.3

cpe:2.3:a:nlnetlabs:unbound:1.19.3
Nlnetlabs » Unbound » Version: 1.2.0

cpe:2.3:a:nlnetlabs:unbound:1.2.0
Nlnetlabs » Unbound » Version: 1.2.1

cpe:2.3:a:nlnetlabs:unbound:1.2.1
Nlnetlabs » Unbound » Version: 1.20.0

cpe:2.3:a:nlnetlabs:unbound:1.20.0
Nlnetlabs » Unbound » Version: 1.21.0

cpe:2.3:a:nlnetlabs:unbound:1.21.0
Nlnetlabs » Unbound » Version: 1.21.1

cpe:2.3:a:nlnetlabs:unbound:1.21.1
Nlnetlabs » Unbound » Version: 1.22.0

cpe:2.3:a:nlnetlabs:unbound:1.22.0
Nlnetlabs » Unbound » Version: 1.23.0

cpe:2.3:a:nlnetlabs:unbound:1.23.0
Nlnetlabs » Unbound » Version: 1.23.1

cpe:2.3:a:nlnetlabs:unbound:1.23.1
Nlnetlabs » Unbound » Version: 1.24.0

cpe:2.3:a:nlnetlabs:unbound:1.24.0
Nlnetlabs » Unbound » Version: 1.24.1

cpe:2.3:a:nlnetlabs:unbound:1.24.1
Nlnetlabs » Unbound » Version: 1.24.2

cpe:2.3:a:nlnetlabs:unbound:1.24.2
Nlnetlabs » Unbound » Version: 1.25.0

cpe:2.3:a:nlnetlabs:unbound:1.25.0
Nlnetlabs » Unbound » Version: 1.25.1

cpe:2.3:a:nlnetlabs:unbound:1.25.1
Nlnetlabs » Unbound » Version: 1.25.2

cpe:2.3:a:nlnetlabs:unbound:1.25.2
Nlnetlabs » Unbound » Version: 1.3.0

cpe:2.3:a:nlnetlabs:unbound:1.3.0
Nlnetlabs » Unbound » Version: 1.3.1

cpe:2.3:a:nlnetlabs:unbound:1.3.1
Nlnetlabs » Unbound » Version: 1.3.2

cpe:2.3:a:nlnetlabs:unbound:1.3.2
Nlnetlabs » Unbound » Version: 1.3.3

cpe:2.3:a:nlnetlabs:unbound:1.3.3
Nlnetlabs » Unbound » Version: 1.3.4

cpe:2.3:a:nlnetlabs:unbound:1.3.4
Nlnetlabs » Unbound » Version: 1.4.0

cpe:2.3:a:nlnetlabs:unbound:1.4.0
Nlnetlabs » Unbound » Version: 1.4.1

cpe:2.3:a:nlnetlabs:unbound:1.4.1
Nlnetlabs » Unbound » Version: 1.4.10

cpe:2.3:a:nlnetlabs:unbound:1.4.10
Nlnetlabs » Unbound » Version: 1.4.11

cpe:2.3:a:nlnetlabs:unbound:1.4.11
Nlnetlabs » Unbound » Version: 1.4.13

cpe:2.3:a:nlnetlabs:unbound:1.4.13
Nlnetlabs » Unbound » Version: 1.4.14

cpe:2.3:a:nlnetlabs:unbound:1.4.14
Nlnetlabs » Unbound » Version: 1.4.15

cpe:2.3:a:nlnetlabs:unbound:1.4.15
Nlnetlabs » Unbound » Version: 1.4.16

cpe:2.3:a:nlnetlabs:unbound:1.4.16
Nlnetlabs » Unbound » Version: 1.4.17

cpe:2.3:a:nlnetlabs:unbound:1.4.17
Nlnetlabs » Unbound » Version: 1.4.18

cpe:2.3:a:nlnetlabs:unbound:1.4.18
Nlnetlabs » Unbound » Version: 1.4.19

cpe:2.3:a:nlnetlabs:unbound:1.4.19
Nlnetlabs » Unbound » Version: 1.4.2

cpe:2.3:a:nlnetlabs:unbound:1.4.2
Nlnetlabs » Unbound » Version: 1.4.20

cpe:2.3:a:nlnetlabs:unbound:1.4.20
Nlnetlabs » Unbound » Version: 1.4.21

cpe:2.3:a:nlnetlabs:unbound:1.4.21
Nlnetlabs » Unbound » Version: 1.4.22

cpe:2.3:a:nlnetlabs:unbound:1.4.22
Nlnetlabs » Unbound » Version: 1.4.3

cpe:2.3:a:nlnetlabs:unbound:1.4.3
Nlnetlabs » Unbound » Version: 1.4.4

cpe:2.3:a:nlnetlabs:unbound:1.4.4
Nlnetlabs » Unbound » Version: 1.4.5

cpe:2.3:a:nlnetlabs:unbound:1.4.5
Nlnetlabs » Unbound » Version: 1.4.6

cpe:2.3:a:nlnetlabs:unbound:1.4.6
Nlnetlabs » Unbound » Version: 1.4.7

cpe:2.3:a:nlnetlabs:unbound:1.4.7
Nlnetlabs » Unbound » Version: 1.4.8

cpe:2.3:a:nlnetlabs:unbound:1.4.8
Nlnetlabs » Unbound » Version: 1.4.9

cpe:2.3:a:nlnetlabs:unbound:1.4.9
Nlnetlabs » Unbound » Version: 1.5.0

cpe:2.3:a:nlnetlabs:unbound:1.5.0
Nlnetlabs » Unbound » Version: 1.5.1

cpe:2.3:a:nlnetlabs:unbound:1.5.1
Nlnetlabs » Unbound » Version: 1.5.10

cpe:2.3:a:nlnetlabs:unbound:1.5.10
Nlnetlabs » Unbound » Version: 1.5.2

cpe:2.3:a:nlnetlabs:unbound:1.5.2
Nlnetlabs » Unbound » Version: 1.5.3

cpe:2.3:a:nlnetlabs:unbound:1.5.3
Nlnetlabs » Unbound » Version: 1.5.4

cpe:2.3:a:nlnetlabs:unbound:1.5.4
Nlnetlabs » Unbound » Version: 1.5.5

cpe:2.3:a:nlnetlabs:unbound:1.5.5
Nlnetlabs » Unbound » Version: 1.5.6

cpe:2.3:a:nlnetlabs:unbound:1.5.6
Nlnetlabs » Unbound » Version: 1.5.6rc1

cpe:2.3:a:nlnetlabs:unbound:1.5.6rc1
Nlnetlabs » Unbound » Version: 1.5.7

cpe:2.3:a:nlnetlabs:unbound:1.5.7
Nlnetlabs » Unbound » Version: 1.5.8

cpe:2.3:a:nlnetlabs:unbound:1.5.8
Nlnetlabs » Unbound » Version: 1.5.9

cpe:2.3:a:nlnetlabs:unbound:1.5.9
Nlnetlabs » Unbound » Version: 1.6.0

cpe:2.3:a:nlnetlabs:unbound:1.6.0
Nlnetlabs » Unbound » Version: 1.6.1

cpe:2.3:a:nlnetlabs:unbound:1.6.1
Nlnetlabs » Unbound » Version: 1.6.2

cpe:2.3:a:nlnetlabs:unbound:1.6.2
Nlnetlabs » Unbound » Version: 1.6.3

cpe:2.3:a:nlnetlabs:unbound:1.6.3
Nlnetlabs » Unbound » Version: 1.6.4

cpe:2.3:a:nlnetlabs:unbound:1.6.4
Nlnetlabs » Unbound » Version: 1.6.5

cpe:2.3:a:nlnetlabs:unbound:1.6.5
Nlnetlabs » Unbound » Version: 1.6.6

cpe:2.3:a:nlnetlabs:unbound:1.6.6
Nlnetlabs » Unbound » Version: 1.6.6-5

cpe:2.3:a:nlnetlabs:unbound:1.6.6-5
Nlnetlabs » Unbound » Version: 1.6.7

cpe:2.3:a:nlnetlabs:unbound:1.6.7
Nlnetlabs » Unbound » Version: 1.6.8

cpe:2.3:a:nlnetlabs:unbound:1.6.8
Nlnetlabs » Unbound » Version: 1.7.0

cpe:2.3:a:nlnetlabs:unbound:1.7.0
Nlnetlabs » Unbound » Version: 1.7.1

cpe:2.3:a:nlnetlabs:unbound:1.7.1
Nlnetlabs » Unbound » Version: 1.7.2

cpe:2.3:a:nlnetlabs:unbound:1.7.2
Nlnetlabs » Unbound » Version: 1.7.3

cpe:2.3:a:nlnetlabs:unbound:1.7.3
Nlnetlabs » Unbound » Version: 1.8.0

cpe:2.3:a:nlnetlabs:unbound:1.8.0
Nlnetlabs » Unbound » Version: 1.8.1

cpe:2.3:a:nlnetlabs:unbound:1.8.1
Nlnetlabs » Unbound » Version: 1.8.2

cpe:2.3:a:nlnetlabs:unbound:1.8.2
Nlnetlabs » Unbound » Version: 1.8.3

cpe:2.3:a:nlnetlabs:unbound:1.8.3
Nlnetlabs » Unbound » Version: 1.9.0

cpe:2.3:a:nlnetlabs:unbound:1.9.0
Nlnetlabs » Unbound » Version: 1.9.2

cpe:2.3:a:nlnetlabs:unbound:1.9.2
Nlnetlabs » Unbound » Version: 1.9.3

cpe:2.3:a:nlnetlabs:unbound:1.9.3
Nlnetlabs » Unbound » Version: 1.9.4

cpe:2.3:a:nlnetlabs:unbound:1.9.4
Nlnetlabs » Unbound » Version: 1.9.5

cpe:2.3:a:nlnetlabs:unbound:1.9.5
Nlnetlabs » Unbound » Version: 1.9.6

cpe:2.3:a:nlnetlabs:unbound:1.9.6

Vulnerabilities

Vulnerable Software

Vulnerability Details CVE-2026-81634

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