Summary
The unbound packages provide a validating, recursive, and caching DNS or DNSSEC resolver.
Security Fix(es):
* unbound: Unbound: Remote Code Execution Vulnerability in CNAME Synthesis (CVE-2026-82717)
* unbound: Unbound: Heap buffer overflow via malicious DNSSEC response (CVE-2026-81634)
* unbound: Unbound: Heap buffer overflow and possible Remote Code Execution when digesting DNSKEY (CVE-2026-81642)
For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.
Fixed packages 1
| Release | Package | Fixed in |
|---|---|---|
| Rocky Linux · 8 | unbound | 0:1.16.2-5.14.el8_10.4 |
Vulnerabilities 3
-
Critical 9.1CVE-2026-81642 Public exploit
Heap buffer overflow and possible Remote Code Execution when digesting DNSKEY
In NLnet Labs Unbound up to and including 1.26.0, a vulnerability was found in the DNSSEC validator that enables denial of service and possible remote code execution as a result of digesting DNSKEYs. A DNSKEY with an owner compression pointer to its own RDATA…
-
High 8.4
CNAME synthesis could lead to heap corruption
In NLnet Labs Unbound up to and including 1.26.0, a vulnerability was found in that can progressively corrupt heap memory and under certain systems and compilation options could lead to remote code execution. The vulnerability starts when CNAME synthesis duri…
-
High 7.5
Possible heap buffer overflow during DNSSEC canonicalization
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 chec…