Unbound DNS Computational Complexity DoS

The vulnerability of the Unbound DNS server is related to the computational complexity of the algorithms involved. Exploiting this vulnerability could allow a malicious actor to cause service interruptions...

CVE-2026-32665

A flaw was found in Unbound when DNS-over-QUIC DoQ is enabled. An attacker could exploit improper validation of client-provided data length, leading to excessive memory allocation. This can cause the system to exceed its configured memory limits for QUIC connections, resulting in a Denial of...

Linux Distros Unpatched Vulnerability : CVE-2026-46582

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available. - In NLnet Labs Unbound 1.6.0 up to and including 1.25.1, a replay of a wildcard rrset as another piece of data, could be briefly considered DNSSEC secure based...

CVE-2026-55990

In NLnet Labs Unbound 1.7.0 up to and including 1.25.1, when the 'dnscrypt:' clause lists more 'dnscrypt-provider-cert:' files than there are matching 'dnscrypt-secret-key:' files, Unbound fills only the matched prefix and leaves the tail slots at the '0xdb' fill that libsodium's allocator writes...

CVE-2026-50046

In NLnet Labs Unbound 1.15.0 up to and including 1.25.1, the TLS server name used for DNS-over-TLS DoT forwarded queries is tied to a struct's 'servicedquery' lifetime but also referenced by another struct 'waitingtcp'. When the owning struct is jostled out of the mesh while the DoT TCP stream is...

CVE-2026-56444

In NLnet Labs Unbound 1.20.0 up to and including 1.25.1, when Unbound is configured with 'serve-expired: yes' and 'serve-expired-client-timeout discard-timeout 0' contrary to the suggested values, the discard-timeout branch during the serve expired logic drops an aged client reply without...

CVE-2026-55973

In NLnet Labs Unbound 1.23.0 up to and including 1.25.1, when 'dns-error-reporting: yes' is set, the EDNS Report-Channel option code 18 from the last upstream response is read and uses the option's length as the length of the agent domain. When a domain name check is performed on the agent domain...

CVE-2026-54478

CVE-2026-54478 affects NLnet Labs Unbound 1.18.0–1.25.1 when listening on a proxy-protocol-port with answer-cookie enabled. The RFC 9018 server-cookie (SipHash) is computed over the proxy’s wire address rather than the PROXYv2-declared client, causing a server cookie to validate for every PROXYv2...

CVE-2026-52863

The CVE concerns NLnet Labs Unbound 1.25.0–1.25.1. A fix that enables coexistence of the respip and dns64 modules creates a shallow copy of the view name, which, under pressure when a configured access-control-view is active and subqueries (respip CNAME redirection, dns64, subnetcache) are attach...

CVE-2026-50046

NLnet Labs Unbound 1.15.0–1.25.1 contains a heap use-after-free in the DoT path. The TLS server name for DoT forwarded queries is tied to a serviced_query object that is also referenced by waiting_tcp. If the owning struct is jostled out of the mesh while DoT TCP handshake is in progress, freeing...

CVE-2026-46582

Affected software/versions: NLnet Labs Unbound 1.6.0 up to and including 1.25.1. Issue: a replay of a wildcard RRset as another piece of data can be momentarily treated as DNSSEC secure based on RRSIG validation and cached, then misvalidated on the serve-expired path due to later NSEC validation,...

CVE-2026-46582

In NLnet Labs Unbound 1.6.0 up to and including 1.25.1, a replay of a wildcard rrset as another piece of data, could be briefly considered DNSSEC secure based only on the RRSIG validation and stored into cache, before later validation treats it as bogus based on NSEC validation. When the resolvin...

CVE-2026-44687 Off-by-one error in 'harden-below-nxdomain' logic can shadow a stub/forward zone by a legitimate parent's NXDOMAIN

In NLnet Labs Unbound 1.13.2 up to and including 1.25.1, stub or forward zones where the name is below an intermediate labed below a DNSSEC signed zone could be shadowed by the intermediate label's secure NXDOMAIN answer from the parent. This is caused by an off-by-one error in...

PT-2026-63392

Name of the Vulnerable Software and Affected Versions NLnet Labs Unbound versions prior to 1.25.2 Description A heap buffer overflow occurs when the validator builds the canonical RDATA form for an RRSIG-covered PX, RP, MINFO, or SOA RRset. The system computes the address of the second embedded...

unbound: Unbound: Cache manipulation via 'ghost domain names' attack

A flaw was found in NLnet Labs Unbound. A remote attacker, by controlling a malicious domain a "ghost zone" and querying a vulnerable Unbound server, could exploit a vulnerability related to "ghost domain names" attacks. This could allow the attacker to overwrite cached Name Server NS records,...

CVE-2026-44390

NLnet Labs Unbound versions up to and including 1.25.0 are vulnerable to a denial of service (DoS) attack due to improper handling of very large Resource Record Sets (RRsets) requiring name compression. Specifically, malicious upstream responses containing large RRsets with records lacking a shar...

Unbound DNS Server Code Execution

The vulnerability of the Unbound DNS server relates to the loading of external, unreliable data alongside reliable data. Exploiting this vulnerability allows a remote attacker to execute arbitrary code...

Unbound DNS Server External Configuration Compromise

The vulnerability of the Unbound DNS server relates to the ability for processes outside the Unbound group to modify the configuration of the Unbound execution environment. Exploiting this vulnerability allows a malicious actor to compromise the confidentiality, integrity, and accessibility of th...

NLnet Labs Unbound Security Vulnerability

NLnet Labs Unbound is an open source DNS server from the Dutch NLnet Labs team. A security vulnerability exists in NLnet Labs Unbound that originates from allowing a remote attacker to cause a denial of service resource consumption by scheduling DNS query accumulation...

Unbound DNS DDoS

The vulnerability of the Unbound DNS server relates to the possibility of generating an impulse flow of a large number of requests to the server, using responses from DNS resolvers. Exploiting this vulnerability allows a malicious actor to carry out a DDoS attack by utilizing DNS traffic...