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In NLnet Labs Unbound up to and including 1.26.0, a vulnerability was found in that can progressively corrupt heap memory and under certain systems… (CVE-2026-82717)

0
Medium
Published: 09/16/2026 (09/16/2026, 09:17:00 UTC)
Source: GCVE Database
Product: unbound

Description

NLnet Labs Unbound up to and including version 1.26.0 contains a vulnerability that can progressively corrupt heap memory. Under certain systems and compilation options, this memory corruption may lead to remote code execution. The issue arises during CNAME synthesis when enforcing a max TTL value, combined with a compression pointer that invalidates the domain name and causes improper buffer position handling. This leads to a heap buffer overflow and potential crash or remote code execution.

CVSS v4.0

Attack Vector
Network
Attack Complexity
High
Attack Requirements
None
Privileges Required
None
User Interaction
None
Vuln. Confidentiality
High
Vuln. Integrity
High
Vuln. Availability
High
Subsq. Confidentiality
High
Subsq. Integrity
High
Subsq. Availability
High
CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/E:U

Affected software

Ubuntu:Pro:14.04:LTSmore threats →ghsa
unbound
pkg:deb/ubuntu/unbound?arch=source&distro=esm-infra-legacy/trusty
Affected versions
=1.4.20-1=1.4.21-1=1.4.21-1ubuntu1=1.4.21-1ubuntu2=1.4.22-1ubuntu1=1.4.22-1ubuntu2=1.4.22-1ubuntu3=1.4.22-1ubuntu4=1.4.22-1ubuntu4.14.04.1=1.4.22-1ubuntu4.14.04.2=1.4.22-1ubuntu4.14.04.3=1.4.22-1ubuntu4.14.04.3+esm1=1.4.22-1ubuntu4.14.04.3+esm2=1.4.22-1ubuntu4.14.04.3+esm3
Ubuntu:Pro:16.04:LTSmore threats →ghsa
unbound
pkg:deb/ubuntu/unbound?arch=source&distro=esm-infra-legacy/xenial
Affected versions
=1.4.22-1ubuntu6=1.5.7-1ubuntu1=1.5.7-1ubuntu2=1.5.8-1ubuntu1=1.5.8-1ubuntu1.1=1.5.8-1ubuntu1.1+esm1=1.5.8-1ubuntu1.1+esm2=1.5.8-1ubuntu1.1+esm3
Ubuntu:Pro:18.04:LTSmore threats →ghsa
unbound
pkg:deb/ubuntu/unbound?arch=source&distro=esm-infra/bionic
Affected versions
=1.6.5-1=1.6.7-1=1.6.7-1build1=1.6.7-1ubuntu1=1.6.7-1ubuntu2=1.6.7-1ubuntu2.1=1.6.7-1ubuntu2.2=1.6.7-1ubuntu2.3=1.6.7-1ubuntu2.4=1.6.7-1ubuntu2.5=1.6.7-1ubuntu2.6=1.6.7-1ubuntu2.6+esm2=1.6.7-1ubuntu2.6+esm3=1.6.7-1ubuntu2.6+esm4
Ubuntu:Pro:20.04:LTSmore threats →ghsa
unbound
pkg:deb/ubuntu/unbound?arch=source&distro=esm-infra/focal
Affected versions
=1.9.0-2ubuntu1=1.9.0-2ubuntu2=1.9.4-2=1.9.4-2ubuntu1=1.9.4-2ubuntu1.1=1.9.4-2ubuntu1.2=1.9.4-2ubuntu1.3=1.9.4-2ubuntu1.4=1.9.4-2ubuntu1.5=1.9.4-2ubuntu1.6=1.9.4-2ubuntu1.8=1.9.4-2ubuntu1.9=1.9.4-2ubuntu1.11=1.9.4-2ubuntu1.11+esm1
Ubuntu:22.04:LTSmore threats →ghsa
unbound
pkg:deb/ubuntu/unbound?arch=source&distro=jammy
Affected versions
=1.13.1-1ubuntu1=1.13.1-1ubuntu3=1.13.1-1ubuntu5=1.13.1-1ubuntu5.1=1.13.1-1ubuntu5.2=1.13.1-1ubuntu5.3=1.13.1-1ubuntu5.4=1.13.1-1ubuntu5.5=1.13.1-1ubuntu5.7=1.13.1-1ubuntu5.8=1.13.1-1ubuntu5.10=1.13.1-1ubuntu5.11=1.13.1-1ubuntu5.12=1.13.1-1ubuntu5.13=1.13.1-1ubuntu5.14=1.13.1-1ubuntu5.15
Ubuntu:24.04:LTSmore threats →ghsa
unbound
pkg:deb/ubuntu/unbound?arch=source&distro=noble
Affected versions
=1.17.1-2=1.18.0-2ubuntu1=1.18.0-2ubuntu2=1.19.1-1ubuntu1=1.19.2-1ubuntu1=1.19.2-1ubuntu3=1.19.2-1ubuntu3.1=1.19.2-1ubuntu3.2=1.19.2-1ubuntu3.3=1.19.2-1ubuntu3.4=1.19.2-1ubuntu3.5=1.19.2-1ubuntu3.6=1.19.2-1ubuntu3.7=1.19.2-1ubuntu3.8=1.19.2-1ubuntu3.9
Ubuntu:26.04:LTSmore threats →ghsa
unbound
pkg:deb/ubuntu/unbound?arch=source&distro=resolute
Affected versions
=1.22.0-2ubuntu2=1.22.0-2ubuntu4=1.24.2-1ubuntu1=1.24.2-1ubuntu2=1.24.2-1ubuntu2.1=1.24.2-1ubuntu2.2

Run on your own infrastructure? Check whether these packages are installed with threat-finder — our free open-source scanner.

AI-Powered Analysis

Machine-generated threat intelligence

AILast updated: 09/24/2026, 06:42:58 UTC

Technical Analysis

CVE-2026-82717 affects NLnet Labs Unbound versions up to and including 1.26.0. The vulnerability is triggered during CNAME synthesis in an upstream DNS response when a max TTL value is rewritten in the packet buffer. A compression pointer referencing the overwritten value invalidates the domain name, causing an error path that fails to properly advance the buffer position. This results in a heap buffer overflow that progressively corrupts heap memory. Depending on system architecture and compilation options, this memory corruption can lead to a crash or remote code execution.

Potential Impact

The vulnerability can cause progressive heap memory corruption, leading to application crashes. On certain systems with specific compilation options, it may allow remote code execution, posing a significant security risk.

Mitigation Recommendations

Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until an official fix is available, users should monitor vendor communications for updates. No vendor advisory or patch links are provided in the current data.

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Technical Details

Gcve Source
db.gcve.eu
Osv Id
UBUNTU-CVE-2026-82717
Osv Schema Version
1.7.0
Ecosystems
["Ubuntu:Pro:14.04:LTS","Ubuntu:Pro:16.04:LTS","Ubuntu:Pro:18.04:LTS","Ubuntu:Pro:20.04:LTS","Ubuntu:22.04:LTS","Ubuntu:24.04:LTS","Ubuntu:26.04:LTS"]
Cvss Version
4.0
State
PUBLISHED

Threat ID: 6ab4be4af7a7c54106f0480d

Added to database: 09/24/2026, 06:08:10 UTC

Last enriched: 09/24/2026, 06:42:58 UTC

Last updated: 09/25/2026, 03:47:33 UTC

Views: 5

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