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Critical ELSA-2026-70754 3 CVEs

Critical: unbound security update (Oracle Linux 8)

Published Sep 24, 2026 · Updated Sep 24, 2026

Summary

[1.16.2-5.14.4]
- Prevent heap corruption during CNAME synthesis (CVE-2026-82717)

[1.16.2-5.14.3]
- Prevent heap buffer overflow when digesting DNSKEY (CVE-2026-81642)
- Prevent heap buffer overflow during DNSSEC canonicalization (CVE-2026-81634)
- Add unit tests for vulnerabilities too

Fixed packages 4

ReleasePackageFixed in
Oracle Linux · 8 python3-unbound 0:1.16.2-5.14.el8_10.4
Oracle Linux · 8 unbound 0:1.16.2-5.14.el8_10.4
Oracle Linux · 8 unbound-devel 0:1.16.2-5.14.el8_10.4
Oracle Linux · 8 unbound-libs 0:1.16.2-5.14.el8_10.4

Vulnerabilities 3

  • Critical 9.1
    CVE-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…