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Fedora 44 : unbound (2026-996b326401)

critical Nessus Plugin ID 349620

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Synopsis

The remote Fedora host is missing one or more security updates.

Description

The remote Fedora 44 host has a package installed that is affected by multiple vulnerabilities as referenced in the FEDORA-2026-996b326401 advisory.

 # Update to 1.26.1 (rhbz#2535076)

 Security fix list from upstream:

 - Fix CVE-2026-81642, Heap buffer overflow and possible Remote Code Execution when digesting DNSKEY.
 Thanks to Yuqi Qiu and Xiang Li from Nankai University, AOSP Lab for the report.
 - Fix CVE-2026-81634, Possible heap buffer overflow during DNSSEC canonicalization. Thanks to Vlatko Kosturjak with Marlink Cyber for the report.
 - Fix CVE-2026-82717, CNAME synthesis could lead to heap corruption. Thanks to Ben Morris from Anthropic for the report.
 - Fix CVE-2026-77955, Possible ZONEMD verification bypass window. Thanks to Yuqi Qiu and Xiang Li from Nankai University, AOSP Lab, In addition, thanks to Qifan Zhang from Palo Alto Networks for also reporting this issue.
 - Fix CVE-2026-78227, Use-after-free in DoQ stream output buffer on reset re-transmission. Thanks to Yuqi Qiu and Xiang Li from Nankai University, AOSP Lab for the report.
 - Fix CVE-2026-80225, Possible degradation of service from continuous queries on the same TCP/DoT connection. Thanks to Qifan Zhang from Palo Alto Networks for the report.
 - Fix CVE-2026-82720, Use-after-free in DoH stream cleanup code path. Thanks to Yuqi Qiu and Xiang Li from Nankai University, AOSP Lab for the report.
 - Fix CVE-2026-85501, Retrap: Novel Vulnerabilities to launch Algorithmic Complexity Attacks on DNSSEC.
 Thanks to Zuyao Xu and Xiang Li from Nankai University, AOSP Lab for report. In addition, thanks to Qifan Zhang from Palo Alto Networks for a complimentary report.
 - Fix CVE-2026-77860, 'serve-expired' can bypass Unbound 'wait-limit'. Thanks to Xuanchao Xie, Lutong Chen, and Kaiping Xue from the University of Science and Technology of China (USTC) for the report.

Tenable has extracted the preceding description block directly from the Fedora security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

Solution

Update the affected unbound package.

See Also

https://bodhi.fedoraproject.org/updates/FEDORA-2026-996b326401

Plugin Details

Severity: Critical

ID: 349620

File Name: fedora_2026-996b326401.nasl

Version: 1.1

Type: Local

Agent: unix

Published: 9/24/2026

Updated: 9/24/2026

Supported Sensors: Frictionless Assessment Agent, Nessus Agent, Agentless Assessment, Continuous Assessment, Tenable Cloud Security, Tenable Self-Hosted Container Security, Nessus

Risk Information

VPR

Risk Factor: Medium

Score: 6.9

Percentile: 96.52

CVSS v2

Risk Factor: Critical

Base Score: 10

Temporal Score: 7.4

Vector: CVSS2#AV:N/AC:L/Au:N/C:C/I:C/A:C

CVSS Score Source: CVE-2026-82717

CVSS v3

Risk Factor: Critical

Base Score: 9.8

Temporal Score: 8.5

Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Temporal Vector: CVSS:3.0/E:U/RL:O/RC:C

CVSS v4

Risk Factor: Critical

Base Score: 10

Threat Score: 9.1

Threat Vector: CVSS:4.0/E:U

Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H

CVSS Score Source: CVE-2026-81642

Vulnerability Information

CPE: cpe:/o:fedoraproject:fedora:44, p-cpe:/a:fedoraproject:fedora:unbound

Required KB Items: Host/local_checks_enabled, Host/RedHat/release, Host/RedHat/rpm-list

Exploit Ease: No known exploits are available

Patch Publication Date: 9/16/2026

Vulnerability Publication Date: 9/16/2026

Reference Information

CVE: CVE-2026-77860, CVE-2026-77955, CVE-2026-78227, CVE-2026-80225, CVE-2026-81634, CVE-2026-81642, CVE-2026-82717, CVE-2026-82720, CVE-2026-85501