Detections
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Echo: unbound: security update to 1.26.1

medium Tenable Self-Hosted Container Security Plugin ID 463744

Description

There are packages installed that are affected by a vulnerability referenced in the following CVE:

 - In NLnet Labs Unbound 1.13.2 up to and including 1.26.1, a vulnerability in ZONEMD configured zones
 (zonemd-check: yes) which are located below (but not at) a trust anchor allow for an attack window where
 (tampered with) zone contents are served (or stored to disk) prior to the ZONEMD integrity check. This is
 caused by the needed DS/DNSKEY asynchronous resolution that needs to happen before the ZONEMD check
 completes. If a zonefile is written to disk (zonefile: option) while the ZONEMD check failed, the tampered
 data are reloaded on startup and available until ZONEMD verification concludes again. If verification
 fails, the data is not served any more but still persists on disk for future reloads. (CVE-2026-77955)

Solution

Update the unbound library and its related packages to version 1.26.1 or later.

See Also

https://advisory.echohq.com/cve/CVE-2026-77955

Plugin Details

Severity: Medium

ID: 463744

Version: Revision 1.1

Type: Local

Published: 10/2/2026

Updated: 10/2/2026

Risk Information

VPR

Risk Factor: Low

Score: 3

Percentile: 23.61

CVSS v2

Risk Factor: Medium

Base Score: 4.6

Temporal Score: 3.4

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

CVSS Score Source: CVE-2026-77955

CVSS v3

Risk Factor: Medium

Base Score: 4.4

Temporal Score: 3.9

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

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

Vulnerability Information

Exploit Ease: No known exploits are available

Patch Publication Date: 9/16/2026

Vulnerability Publication Date: 9/16/2026

Reference Information

CVE: CVE-2026-77955

IAVA: 2026-A-1070