Detections
Analytics

Echo: unbound: security update to 1.25.1-1

critical Tenable Self-Hosted Container Security Plugin ID 458074

Description

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

 - NLnet Labs Unbound 1.19.1 up to and including version 1.25.0 has a vulnerability in the DNSSEC validator
 that enables denial of service and possible remote code execution as a result of deep copying a data
 structure and erroneously overwriting a destination pointer. An adversary can exploit the vulnerability by
 controlling a malicious signed zone and querying a vulnerable Unbound. When DS sub-queries need to suspend
 validation due to NSEC3 computational budget exhaustion (introduced in Unbound 1.19.1), Unbound deep-
 copies response messages to preserve them across memory region teardown. A struct-assignment bug
 overwrites the destination's pointer with the source's pointer. After the sub-query region is freed, the
 resumed validator dereferences this dangling pointer, triggering a crash or potentially enabling arbitrary
 code execution. Unbound 1.25.1 contains a patch with a fix to preserve the correct pointer when deep
 copying the data structure. (CVE-2026-33278)

Solution

Update the unbound library and its related packages to version 1.25.1-1 or later.

See Also

https://advisory.echohq.com/cve/CVE-2026-33278

Plugin Details

Severity: Critical

ID: 458074

Version: Revision 1.2

Type: Local

Published: 10/2/2026

Updated: 10/5/2026

Supported Sensors: Tenable Cloud Security, Tenable Self-Hosted Container Security

Risk Information

VPR

Risk Factor: High

Score: 7.6

Percentile: 98.3

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-2026-33278

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

Vulnerability Information

Exploit Ease: No known exploits are available

Patch Publication Date: 5/21/2026

Vulnerability Publication Date: 5/20/2026

Reference Information

CVE: CVE-2026-33278