CVE-2026-42959 Crash during DNSSEC validation of malicious content

NLnet Labs Unbound up to and including version 1.25.0 has a denial of service vulnerability in the DNSSEC validator that can lead to a crash given malicious upstream replies. When Unbound constructs chase-reply messages for validation, the code uses the wrong counter to calculate write offsets fo...

CVE-2026-42959

NLnet Labs Unbound up to and including version 1.25.0 has a denial of service vulnerability in the DNSSEC validator that can lead to a crash given malicious upstream replies. When Unbound constructs chase-reply messages for validation, the code uses the wrong counter to calculate write offsets fo...

CVE-2026-42959

CVE-2026-42959 affects NLnet Labs Unbound up to version 1.25.0. The vulnerability lies in the DNSSEC validator: while constructing chase-reply messages, the code uses the wrong counter to calculate write offsets for ADDITIONAL section rrsets. This, combined with DNAME duplication increasing the A...

CVE-2026-42944

NLnet Labs Unbound 1.14.0 up to and including version 1.25.0 has a vulnerability that results in heap overflow when encoding multiple NSID and/or DNS Cookie EDNS and/or EDNS Padding options in the reply packet. The relevant options 'nsid', 'answer-cookie', 'pad-responses' default need to be enabl...

CVE-2026-42944

NLnet Labs Unbound 1.14.0 up to and including version 1.25.0 has a vulnerability that results in heap overflow when encoding multiple NSID and/or DNS Cookie EDNS and/or EDNS Padding options in the reply packet. The relevant options 'nsid', 'answer-cookie', 'pad-responses' default need to be enabl...

EUVD-2026-31085

NLnet Labs Unbound 1.14.0 up to and including version 1.25.0 has a vulnerability that results in heap overflow when encoding multiple NSID and/or DNS Cookie EDNS and/or EDNS Padding options in the reply packet. The relevant options 'nsid', 'answer-cookie', 'pad-responses' default need to be enabl...

CVE-2026-42944 Heap overflow with multiple NSID, COOKIE, PADDING EDNS options

NLnet Labs Unbound 1.14.0 up to and including version 1.25.0 has a vulnerability that results in heap overflow when encoding multiple NSID and/or DNS Cookie EDNS and/or EDNS Padding options in the reply packet. The relevant options 'nsid', 'answer-cookie', 'pad-responses' default need to be enabl...

CVE-2026-42944

NLnet Labs Unbound 1.14.0–1.25.0 is affected by a heap overflow when encoding multiple NSID and/or DNS Cookie EDNS and/or EDNS Padding options in replies. The vulnerability requires the options (nsid, answer-cookie, pad-responses) to be enabled, and a querier can trigger the overflow by attaching...

EUVD-2026-31081

NLnet Labs Unbound up to and including version 1.25.0 has a vulnerability in the DNSSEC validator where the code path to consult the negative cache for DS records does not take into account the limit on NSEC3 hash calculations introduced in 1.19.1. This leads to degradation of service during the...

CVE-2026-42923

NLnet Labs Unbound up to and including version 1.25.0 has a vulnerability in the DNSSEC validator where the code path to consult the negative cache for DS records does not take into account the limit on NSEC3 hash calculations introduced in 1.19.1. This leads to degradation of service during the...

CVE-2026-42923 Degradation of service with unbounded NSEC3 hash calculations

NLnet Labs Unbound up to and including version 1.25.0 has a vulnerability in the DNSSEC validator where the code path to consult the negative cache for DS records does not take into account the limit on NSEC3 hash calculations introduced in 1.19.1. This leads to degradation of service during the...

CVE-2026-42923 Degradation of service with unbounded NSEC3 hash calculations

NLnet Labs Unbound up to and including version 1.25.0 has a vulnerability in the DNSSEC validator where the code path to consult the negative cache for DS records does not take into account the limit on NSEC3 hash calculations introduced in 1.19.1. This leads to degradation of service during the...

EUVD-2026-31082

NLnet Labs Unbound up to and including version 1.25.0 has a vulnerability in the jostle logic that could defeat its purpose and degrade resolution performance. Retransmits of the same query could renew the age of slow running queries and not allow the jostle logic to see them as aged and potentia...

CVE-2026-42534

NLnet Labs Unbound up to and including version 1.25.0 has a vulnerability in the jostle logic that can degrade DNS resolution performance and, under coordinated attack, lead to denial of service. An adversary controlling a slow or malicious DNS server can cause duplicate slow queries to skew agin...

CVE-2026-42534

NLnet Labs Unbound up to and including version 1.25.0 has a vulnerability in the jostle logic that could defeat its purpose and degrade resolution performance. Retransmits of the same query could renew the age of slow running queries and not allow the jostle logic to see them as aged and potentia...

CVE-2026-42534

NLnet Labs Unbound up to and including version 1.25.0 has a vulnerability in the jostle logic that could defeat its purpose and degrade resolution performance. Retransmits of the same query could renew the age of slow running queries and not allow the jostle logic to see them as aged and potentia...

CVE-2026-42534 Jostle logic bypass degrades resolution performance

NLnet Labs Unbound up to and including version 1.25.0 has a vulnerability in the jostle logic that could defeat its purpose and degrade resolution performance. Retransmits of the same query could renew the age of slow running queries and not allow the jostle logic to see them as aged and potentia...

CVE-2026-41292

CVE-2026-41292 affects NLnet Labs Unbound up to 1.25.0. A vulnerability in parsing long lists of incoming EDNS options can cause a degradation of service/DoS as adversaries send queries with many EDNS options, tying up worker threads while parsing. The issue is mitigated in Unbound 1.25.1, which ...

CVE-2026-41292 Long list of incoming EDNS options degrades performance

NLnet Labs Unbound up to and including version 1.25.0 is vulnerable to a degradation of service attack related to parsing long lists of incoming EDNS options. An adversary sending queries with too many EDNS options can hold Unbound threads hostage while they are parsing and creating internal data...

CVE-2026-41292 Long list of incoming EDNS options degrades performance

NLnet Labs Unbound up to and including version 1.25.0 is vulnerable to a degradation of service attack related to parsing long lists of incoming EDNS options. An adversary sending queries with too many EDNS options can hold Unbound threads hostage while they are parsing and creating internal data...