Detections
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Echo: unbound: security update to 1.26.1

high Tenable Cloud Security Plugin ID 460747

Description

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

 - 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 check. A malicious actor operating a malicious name server or
 tampering with an incoming response to Unbound (canonicalisation happens before DNSSEC validation), can
 trigger the vulnerability. (CVE-2026-81634)

Solution

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

See Also

https://advisory.echohq.com/cve/CVE-2026-81634

Plugin Details

Severity: High

ID: 460747

Version: Revision 1.1

Type: Local

Published: 10/2/2026

Updated: 10/2/2026

Risk Information

VPR

Risk Factor: Low

Score: 3

Percentile: 23.63

CVSS v2

Risk Factor: High

Base Score: 7.8

Temporal Score: 5.8

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

CVSS Score Source: CVE-2026-81634

CVSS v3

Risk Factor: High

Base Score: 7.5

Temporal Score: 6.5

Vector: CVSS:3.0/AV:N/AC:L/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: 9/16/2026

Vulnerability Publication Date: 9/16/2026

Reference Information

CVE: CVE-2026-81634

IAVA: 2026-A-1070