7.5
High
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…
Description
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.
Affected products and versions
| Product | Affected versions | Fixed in |
|---|---|---|
| unbound 1.26 | earliest → < 1.26.1 | 1.26.1 |
Other CVEs of unbound
The 58 CVEs of unbound →
CVE-2026-97206
NLnet Labs Unbound, 1.22.0 up to and including version 1.26.1, contains a DNS-over-QUIC (DoQ) lifetime bug reachable…
7.5
High
CVE-2026-96405
NLnet Labs Unbound up to and including version 1.26.1 limits compression-pointer traversal for each individual…
5.3
Medium
CVE-2026-50106
When NLnet Labs Unbound up to and including version 1.26.1 is configured with both a root trust anchor and an additional…
6.5
Medium
CVE-2026-35501
When NLnet Labs Unbound 1.0.1 up to and including version 1.26.1 is configured with both a root trust anchor and an…
3.7
Low