EUVD-2026-47676

In NLnet Labs Unbound 1.4.22 up to and including 1.25.1, UDP source port is randomized and intended to serve as a secret value that increases the entropy of DNS transactions. When resolver load balancing policies depend on the source port while their outcome is revealed this secrecy is undermined...

CVE-2026-50252

In NLnet Labs Unbound 1.4.22 up to and including 1.25.1, UDP source port is randomized and intended to serve as a secret value that increases the entropy of DNS transactions. When resolver load balancing policies depend on the source port while their outcome is revealed this secrecy is undermined...

CVE-2026-50251 Attacker supplied '0.0.0.0'/'::' glue triggers defensive full-cache flush

In NLnet Labs Unbound up to and including version 1.25.1, when 'unwanted-reply-threshold' is enabled set to any value greater than zero, glue records of 0.0.0.0/::0 can short-circuit Unbound, on systems that can direct such traffic, by issuing DNS queries and receiving seemingly unwanted replies...

CVE-2026-50248

In NLnet Labs Unbound 1.7.0 up to and including 1.25.1, when an auth/rpz zone has a configured primary hostname that resolves to BOGUS A/AAAA, it is still considered as a possible XFR endpoint. A malicious actor that can spoof the hostname's A/AAAA record no valid RRSIG required becomes the zone'...

CVE-2026-50243 'response-ip'/'rpz' can rewrite BOGUS answers instead of returning SERVFAIL

In NLnet Labs Unbound 1.6.2 up to and including 1.25.1, when Unbound is configured with the 'respip' module in front of the validator together with a 'response-ip' redirect rule or an RPZ file with an RPZ-IP trigger, the rewriting handler does not check the security status of the upstream answer...

EUVD-2026-47673

In NLnet Labs Unbound 1.6.2 up to and including 1.25.1, when Unbound is configured with the 'respip' module in front of the validator together with a 'response-ip' redirect rule or an RPZ file with an RPZ-IP trigger, the rewriting handler does not check the security status of the upstream answer...

CVE-2026-50243

In NLnet Labs Unbound 1.6.2 up to and including 1.25.1, when Unbound is configured with the 'respip' module in front of the validator together with a 'response-ip' redirect rule or an RPZ file with an RPZ-IP trigger, the rewriting handler does not check the security status of the upstream answer...

CVE-2026-50046 Possible heap use-after-free in an error path when a DoT forwarded query is jostled out

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-2026-50046 Possible heap use-after-free in an error path when a DoT forwarded query is jostled out

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-2026-50046

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-2026-50046

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...

EUVD-2026-47672

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-2026-50045

In NLnet Labs Unbound 1.22.0 up to and including 1.25.1, a single client query for a deeply nested name under a DNSSEC-signed parent can cause Unbound to send more upstream packets per client query than the configured 'max-global-quota'. This effectively bypasses a security configuration that...

CVE-2026-44690

The CVE-2026-44690 entry concerns NLnet Labs Unbound versions 1.7.0 through 1.25.1 where insufficient validation of the RRSIG.Labels field combined with premature cache writes during RFC 8198 aggressive NSEC processing enables cache poisoning. A malicious actor controlling a single delegated zone...

CVE-2026-44690 Cross-zone wildcard cache poisoning via RRSIG.labels manipulation

In NLnet Labs Unbound 1.7.0 up to and including 1.25.1, insufficient validation of the RRSIG.Labels field combined with premature cache writes during RFC 8198 aggressive NSEC processing leads to cache poisoning that permits a malicious actor controlling a single delegated zone to poison arbitrary...

CVE-2026-44687

CVE-2026-44687 affects NLnet Labs Unbound releases 1.13.2 through 1.25.1. A bug in the default tallied logic for hardened-below-nxdomain can cause a stub or forward zone to be shadowed by a DNSSEC-secure NXDOMAIN answer at the parent when the query name is an intermediate label below a signed zon...

EUVD-2026-47666

In NLnet Labs Unbound 1.16.2 up to and including 1.25.1, a similar vulnerability as with CVE-2026-40622 in the 'ghost domain names' family of attacks was found in Unbound that could extend the ghost domain window by up to one cached TTL configured value for A/AAAA glue records. Similar to other...

CVE-2026-41637

In NLnet Labs Unbound 1.22.0 up to and including 1.25.1, client terminated DNS-over-QUIC DoQ queries are not accounted properly by Unbound resulting in low-cost inflation of the waiting number of replies for already in-flight resolution queries. This results in degradation of resolution service f...

CVE-2026-41637

CVE-2026-41637 affects NLnet Labs Unbound (versions 1.22.0 to 1.25.1). The vulnerability arises when client-terminated DNS-over-QUIC (DoQ) queries are not counted properly, allowing a low-cost inflation of the waiting queue for in-flight queries and causing degradation of resolution service for n...

CVE-2026-41637 Degradation of resolution service from improperly accounted client-terminated DNS-over-QUIC queries

In NLnet Labs Unbound 1.22.0 up to and including 1.25.1, client terminated DNS-over-QUIC DoQ queries are not accounted properly by Unbound resulting in low-cost inflation of the waiting number of replies for already in-flight resolution queries. This results in degradation of resolution service f...