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This CVE record has been updated after NVD enrichment efforts were completed. Enrichment data supplied by the NVD may require amendment due to these changes.
Description
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.
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Title: Unbound de NLnet Labs, Description: NLnet Labs Unbound 1.19.1 hasta la versión 1.25.0 inclusive tiene una vulnerabilidad en el validador DNSSEC que permite la denegación de servicio y posible ejecución remota de código como resultado de la copia profunda de una estructura de datos y la sobrescritura errónea de un puntero de destino. Un adversario puede explotar la vulnerabilidad controlando una zona firmada maliciosa y consultando un Unbound vulnerable. Cuando las subconsultas DS necesitan suspender la validación debido al agotamiento del presupuesto computacional de NSEC3 (introducido en Unbound 1.19.1), Unbound realiza copias profundas de los mensajes de respuesta para preservarlos durante la desasignación de la región de memoria. Un error de asignación de estructura sobrescribe el puntero del destino con el puntero del origen. Después de que se libera la región de la subconsulta, el validador reanudado desreferencia este puntero colgante, lo que provoca un fallo o potencialmente permite la ejecución de código arbitrario. Unbound 1.25.1 contiene un parche con una corrección para preservar el puntero correcto al realizar la copia profunda de la estructura de datos.
CVE Modified by redhat-SADP7/14/2026 10:20:12 PM
Action
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New Value
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Affected
[{"vendor":"Red Hat","product":"Red Hat Enterprise Linux AppStream (v. 10)","defaultStatus":"affected","cpes":["cpe:/o:redhat:enterprise_linux:10.2"]},{"vendor":"Red Hat","product":"Red Hat Enterprise Linux AppStream (v. 9)","defaultStatus":"affected","cpes":["cpe:/a:redhat:enterprise_linux:9::appstream"]},{"vendor":"Red Hat","product":"Red Hat Enterprise Linux CodeReady Linux Builder (v. 10)","defaultStatus":"affected","cpes":["cpe:/o:redhat:enterprise_linux:10.2"]},{"vendor":"Red Hat","product":"Red Hat Enterprise Linux CodeReady Linux Builder (v. 9)","defaultStatus":"affected","cpes":["cpe:/a:redhat:enterprise_linux:9::crb"]},{"vendor":"Red Hat","product":"Red Hat Hardened Images","defaultStatus":"affected","cpes":["cpe:/a:redhat:hummingbird:1"]},{"vendor":"Red Hat","product":"Red Hat Enterprise Linux 6","defaultStatus":"affected","cpes":["cpe:/o:redhat:enterprise_linux:6"]},{"vendor":"Red Hat","product":"Red Hat OpenShift Container Platform 4","defaultStatus":"affected","cpes":["cpe:/a:redhat:openshift:4"]},{"vendor":"Red Hat","product":"Red Hat Enterprise Linux 7","defaultStatus":"unaffected","cpes":["cpe:/o:redhat:enterprise_linux:7"]},{"vendor":"Red Hat","product":"Red Hat Enterprise Linux 8","defaultStatus":"unaffected","cpes":["cpe:/o:redhat:enterprise_linux:8"]}]
[{"vendor":"Red Hat","product":"Red Hat Enterprise Linux 10","defaultStatus":"affected","collectionURL":"https://access.redhat.com/downloads/content/package-browser/","packageName":"unbound","cpes":["cpe:/o:redhat:enterprise_linux:10.2"],"versions":[{"version":"0:1.24.2-7.el10_2.1","lessThan":"*","versionType":"rpm","status":"unaffected"}]},{"vendor":"Red Hat","product":"Red Hat Enterprise Linux 9","defaultStatus":"affected","collectionURL":"https://access.redhat.com/downloads/content/package-browser/","packageName":"unbound","cpes":["cpe:/a:redhat:enterprise_linux:9"],"versions":[{"version":"0:1.24.2-3.el9_8.1","lessThan":"*","versionType":"rpm","status":"unaffected"}]},{"vendor":"Red Hat","product":"Red Hat Hardened Images","defaultStatus":"affected","collectionURL":"https://access.redhat.com/downloads/content/package-browser/","packageName":"unbound-main","cpes":["cpe:/a:redhat:hummingbird:1"],"versions":[{"version":"1.25.1-0.1.hum1","lessThan":"*","versionType":"rpm","status":"unaffected"}]},{"vendor":"Red Hat","product":"Red Hat Enterprise Linux 6","defaultStatus":"unknown","collectionURL":"https://access.redhat.com/downloads/content/package-browser/","packageName":"unbound","cpes":["cpe:/o:redhat:enterprise_linux:6"]},{"vendor":"Red Hat","product":"Red Hat Enterprise Linux 7","defaultStatus":"unaffected","collectionURL":"https://access.redhat.com/downloads/content/package-browser/","packageName":"unbound","cpes":["cpe:/o:redhat:enterprise_linux:7"]},{"vendor":"Red Hat","product":"Red Hat Enterprise Linux 8","defaultStatus":"unaffected","collectionURL":"https://access.redhat.com/downloads/content/package-browser/","packageName":"unbound","cpes":["cpe:/o:redhat:enterprise_linux:8"]},{"vendor":"Red Hat","product":"Red Hat OpenShift Container Platform 4","defaultStatus":"affected","collectionURL":"https://access.redhat.com/downloads/content/package-browser/","packageName":"rhcos","cpes":["cpe:/a:redhat:openshift:4"]}]
[{"vendor":"Red Hat","product":"Red Hat Enterprise Linux AppStream (v. 10)","defaultStatus":"affected","cpes":["cpe:/o:redhat:enterprise_linux:10.2"]},{"vendor":"Red Hat","product":"Red Hat Enterprise Linux AppStream (v. 9)","defaultStatus":"affected","cpes":["cpe:/a:redhat:enterprise_linux:9::appstream"]},{"vendor":"Red Hat","product":"Red Hat Enterprise Linux CodeReady Linux Builder (v. 10)","defaultStatus":"affected","cpes":["cpe:/o:redhat:enterprise_linux:10.2"]},{"vendor":"Red Hat","product":"Red Hat Enterprise Linux CodeReady Linux Builder (v. 9)","defaultStatus":"affected","cpes":["cpe:/a:redhat:enterprise_linux:9::crb"]},{"vendor":"Red Hat","product":"Red Hat Hardened Images","defaultStatus":"affected","cpes":["cpe:/a:redhat:hummingbird:1"]},{"vendor":"Red Hat","product":"Red Hat Enterprise Linux 6","defaultStatus":"affected","cpes":["cpe:/o:redhat:enterprise_linux:6"]},{"vendor":"Red Hat","product":"Red Hat OpenShift Container Platform 4","defaultStatus":"affected","cpes":["cpe:/a:redhat:openshift:4"]},{"vendor":"Red Hat","product":"Red Hat Enterprise Linux 7","defaultStatus":"unaffected","cpes":["cpe:/o:redhat:enterprise_linux:7"]},{"vendor":"Red Hat","product":"Red Hat Enterprise Linux 8","defaultStatus":"unaffected","cpes":["cpe:/o:redhat:enterprise_linux:8"]}]
New CVE Received from NLnet Labs5/20/2026 6:16:26 AM
Action
Type
Old Value
New Value
Added
Description
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.
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