Detections
Analytics

Echo: unbound: security update to 1.25.2

medium Tenable Cloud Security Plugin ID 458487

Description

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

 - In NLnet Labs Unbound 1.25.0 up to and including 1.25.1, a fix that makes the 'respip' and 'dns64' modules
 work together, creates a shallow copy of the view name in effect that could lead to memory corruption if
 the owner of the original view name is jostled out when Unbound is under pressure. Unbound needs to be
 configured with one of 'respip'/'rpz' modules, together with a module that can attach subqueries (respip
 CNAME redirection, dns64, subnetcache) and a configured 'access-control-view' while Unbound is under
 pressure so that joslte logic kicks in and starts dropping slow queries. The subquery is getting a shallow
 copy of the view name and if the super query which owns the view name is jostled out, memory corruption
 can occur. Likelihood of a crash is low, since it relies heavily on the underlying memory allocator and
 the memory layout. Debug memory builds (e.g., ASAN) that catch the free terminate the server.
 (CVE-2026-52863)

Solution

Update the unbound library and its related packages to version 1.25.2 or later.

See Also

https://advisory.echohq.com/cve/CVE-2026-52863

Plugin Details

Severity: Medium

ID: 458487

Version: Revision 1.1

Type: Local

Published: 10/2/2026

Updated: 10/2/2026

Risk Information

VPR

Risk Factor: Low

Score: 3

Percentile: 23.74

CVSS v2

Risk Factor: Medium

Base Score: 5.4

Temporal Score: 4

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

CVSS Score Source: CVE-2026-52863

CVSS v3

Risk Factor: Medium

Base Score: 5.9

Temporal Score: 5.2

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

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

Vulnerability Information

Exploit Ease: No known exploits are available

Patch Publication Date: 7/23/2026

Vulnerability Publication Date: 7/22/2026

Reference Information

CVE: CVE-2026-52863