DEBIAN-CVE-2026-33278

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Source
https://security-tracker.debian.org/tracker/CVE-2026-33278
Import Source
https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-33278.json
JSON Data
https://api.osv.dev/v1/vulns/DEBIAN-CVE-2026-33278
Upstream
  • CVE-2026-33278
Published
2026-05-20T10:16:26.530Z
Modified
2026-05-27T23:00:21.221784906Z
Severity
  • 9.8 (Critical) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H CVSS Calculator
Summary
[none]
Details

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.

References

Affected packages

Debian:11 / unbound

Package

Name
unbound
Purl
pkg:deb/debian/unbound?arch=source&distro=bullseye

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected

Affected versions

1.*
1.13.1-1
1.13.1-1+deb11u1
1.13.1-1+deb11u2
1.13.1-1+deb11u3
1.13.1-1+deb11u4
1.13.1-1+deb11u5
1.13.1-1+deb11u6
1.13.1-1+deb11u7
1.13.1-1.1
1.15.0-1
1.15.0-2
1.15.0-3
1.15.0-4
1.15.0-5
1.15.0-6
1.15.0-7
1.15.0-8
1.15.0-9
1.15.0-10
1.15.0-11
1.16.0-1
1.16.0-2
1.16.2-1
1.16.3-1
1.17.0-1
1.17.1-1~bpo11+1
1.17.1-1
1.17.1-2~bpo11+1
1.17.1-2
1.17.1-2+loong64
1.18.0-1
1.18.0-2
1.19.1-1
1.19.2-1
1.20.0-1
1.21.1-1
1.22.0-1
1.22.0-2
1.23.1-1
1.24.0-1
1.24.0-2
1.24.1-1
1.24.1-2
1.24.2-1
1.25.0-1
1.25.1-1

Ecosystem specific 

{
    "urgency": "not yet assigned"
}

Database specific

source 
"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-33278.json"

Debian:12 / unbound

Package

Name
unbound
Purl
pkg:deb/debian/unbound?arch=source&distro=bookworm

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected

Affected versions

1.*
1.17.1-2
1.17.1-2+deb12u1
1.17.1-2+deb12u2
1.17.1-2+deb12u3
1.17.1-2+deb12u4
1.17.1-2+loong64
1.18.0-1
1.18.0-2
1.19.1-1
1.19.2-1
1.20.0-1
1.21.1-1
1.22.0-1
1.22.0-2
1.23.1-1
1.24.0-1
1.24.0-2
1.24.1-1
1.24.1-2
1.24.2-1
1.25.0-1
1.25.1-1

Ecosystem specific 

{
    "urgency": "not yet assigned"
}

Database specific

source 
"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-33278.json"

Debian:13 / unbound

Package

Name
unbound
Purl
pkg:deb/debian/unbound?arch=source&distro=trixie

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected
Fixed
1.22.0-2+deb13u3

Affected versions

1.*
1.22.0-2
1.22.0-2+deb13u1
1.22.0-2+deb13u2

Ecosystem specific 

{
    "urgency": "not yet assigned"
}

Database specific

source 
"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-33278.json"

Debian:14 / unbound

Package

Name
unbound
Purl
pkg:deb/debian/unbound?arch=source&distro=forky

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected
Fixed
1.25.1-1

Affected versions

1.*
1.22.0-2
1.23.1-1
1.24.0-1
1.24.0-2
1.24.1-1
1.24.1-2
1.24.2-1
1.25.0-1

Ecosystem specific 

{
    "urgency": "not yet assigned"
}

Database specific

source 
"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-33278.json"