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OpenAdvisories
Critical RHSA-2026:70754 3 CVEs

Red Hat Security Advisory: unbound security update

Published Sep 24, 2026 · Updated Oct 19, 2026

Ecosystem: Red Hat

Fixed packages 8

ReleasePackageFixed in
Red Hat · RHEL 8 enterprise_linux:8::appstream python3-unbound 0:1.16.2-5.14.el8_10.4
Red Hat · RHEL 8 enterprise_linux:8::appstream python3-unbound-debuginfo 0:1.16.2-5.14.el8_10.4
Red Hat · RHEL 8 enterprise_linux:8::appstream unbound 0:1.16.2-5.14.el8_10.4
Red Hat · RHEL 8 enterprise_linux:8::appstream unbound-debuginfo 0:1.16.2-5.14.el8_10.4
Red Hat · RHEL 8 enterprise_linux:8::appstream unbound-debugsource 0:1.16.2-5.14.el8_10.4
Red Hat · RHEL 8 enterprise_linux:8::appstream unbound-devel 0:1.16.2-5.14.el8_10.4
Red Hat · RHEL 8 enterprise_linux:8::appstream unbound-libs 0:1.16.2-5.14.el8_10.4
Red Hat · RHEL 8 enterprise_linux:8::appstream unbound-libs-debuginfo 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…

    NLnet Labs Unbound unbound unbound Debian Ubuntu Azure Linux Alpine
  • High 8.4
    CVE-2026-82717

    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…

    NLnet Labs Unbound unbound unbound Debian Ubuntu Azure Linux Alpine
  • High 7.5
    CVE-2026-81634

    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…

    NLnet Labs Unbound unbound unbound Debian Ubuntu Azure Linux

References

  • article
    https://access.redhat.com/security/updates/classification/#critical
  • report
    https://bugzilla.redhat.com/show_bug.cgi?id=2535051
  • report
    https://bugzilla.redhat.com/show_bug.cgi?id=2535054
  • report
    https://bugzilla.redhat.com/show_bug.cgi?id=2535059
  • advisory
    https://security.access.redhat.com/data/csaf/v2/advisories/2026/rhsa-2026_70754.json
  • report
    https://access.redhat.com/security/cve/CVE-2026-81634
  • advisory
    https://www.cve.org/CVERecord?id=CVE-2026-81634
  • advisory
    https://nvd.nist.gov/vuln/detail/CVE-2026-81634
  • article
    https://www.nlnetlabs.nl/downloads/unbound/CVE-2026-81634.txt
  • report
    https://access.redhat.com/security/cve/CVE-2026-81642
  • advisory
    https://www.cve.org/CVERecord?id=CVE-2026-81642
  • advisory
    https://nvd.nist.gov/vuln/detail/CVE-2026-81642
  • article
    https://www.nlnetlabs.nl/downloads/unbound/CVE-2026-81642.txt
  • report
    https://access.redhat.com/security/cve/CVE-2026-82717
  • advisory
    https://www.cve.org/CVERecord?id=CVE-2026-82717
  • advisory
    https://nvd.nist.gov/vuln/detail/CVE-2026-82717
  • article
    https://www.nlnetlabs.nl/downloads/unbound/CVE-2026-82717.txt