USN-8474-1: NSD vulnerabilities

It was discovered that NSD incorrectly handled APL resource records with an address length larger than permitted for the address family. A remote attacker could use this to cause a stack-based buffer overflow when the zone is written to disk, potentially executing arbitrary code with the privileg...

CVE-2026-40209

CVE-2026-40209 describes a denial-of-service risk where an attacker can send IXFR queries causing outgoing TCP connections to a backend to remain open until timeouts, potentially exhausting available file descriptors or hitting concurrent-connection limits. The core issue is a hang/linger conditi...

CVE-2026-40209 Denial of service via IXFR queries

An attacker might be able to cause outgoing TCP connections to backend to be stuck until a timeout occurs instead of being released immediately, by sending IXFR queries. This could be used to cause a denial of service if there is a limit to the number of concurrent connections to this backend, or...

CVE-2026-40209

An attacker might be able to cause outgoing TCP connections to backend to be stuck until a timeout occurs instead of being released immediately, by sending IXFR queries. This could be used to cause a denial of service if there is a limit to the number of concurrent connections to this backend, or...

CVE-2026-40209 Denial of service via IXFR queries

An attacker might be able to cause outgoing TCP connections to backend to be stuck until a timeout occurs instead of being released immediately, by sending IXFR queries. This could be used to cause a denial of service if there is a limit to the number of concurrent connections to this backend, or...

EUVD-2026-39348

An attacker might be able to cause outgoing TCP connections to backend to be stuck until a timeout occurs instead of being released immediately, by sending IXFR queries. This could be used to cause a denial of service if there is a limit to the number of concurrent connections to this backend, or...

EUVD-2026-39184

NSD version 4.14.0 introduced a bug where a specially crafted APL RR, with an adflength larger than permitted for the address family will overwrite the stack when the zone is written to disk, with a maximum of 111 attacker controlled bytes...

EUVD-2026-39182

If NSD is configured as secondary for a zone, the primary of that zone can crash NSD with an AXFR containing a DNS message with a special crafted SVCB RR with an rdata size of 65512, that let's an uint16t variable that is used to allocate space needed for the RR wrap because total size 65535,...

CVE-2026-12244

If NSD is configured as secondary for a zone, the primary of that zone can crash NSD with an AXFR containing a DNS message with a special crafted SVCB RR with an rdata size of 65512, that let's an uint16t variable that is used to allocate space needed for the RR wrap because total size 65535,...

CVE-2026-12244

If NSD is configured as secondary for a zone, the primary of that zone can crash NSD with an AXFR containing a DNS message with a special crafted SVCB RR with an rdata size of 65512, that let's an uint16t variable that is used to allocate space needed for the RR wrap because total size 65535,...

ALPINE-CVE-2026-12244

If NSD is configured as secondary for a zone, the primary of that zone can crash NSD with an AXFR containing a DNS message with a special crafted SVCB RR with an rdata size of 65512, that let's an uint16t variable that is used to allocate space needed for the RR wrap because total size 65535,...

CVE-2026-12490

When a provide-xfr is given with a tls-auth-name, a secondary requesting a transfer should provide a client certificate with that name. However, no client certificate is needed when the request comes in over TLS over the regular tls-port and not the tls-auth-port or over over TCP over the regular...

CVE-2026-12246

NSD version 4.14.0 introduced a bug where a specially crafted APL RR, with an adflength larger than permitted for the address family will overwrite the stack when the zone is written to disk, with a maximum of 111 attacker controlled bytes...

CVE-2026-12246 Out of bounds stack write with crafted APL RR

NSD version 4.14.0 introduced a bug where a specially crafted APL RR, with an adflength larger than permitted for the address family will overwrite the stack when the zone is written to disk, with a maximum of 111 attacker controlled bytes...

CVE-2026-12246

NSD 4.14.0 contains a vulnerability where a specially crafted APL RR with adflength exceeding the address family limit can cause a stack overwrite when writing the zone to disk, allowing up to 111 attacker-controlled bytes to influence memory. This is a data/stack corruption issue that affects th...

CVE-2026-12244

If NSD is configured as secondary for a zone, the primary of that zone can crash NSD with an AXFR containing a DNS message with a special crafted SVCB RR with an rdata size of 65512, that let's an uint16t variable that is used to allocate space needed for the RR wrap because total size 65535,...

CVE-2026-12244

If NSD is configured as secondary for a zone, the primary of that zone can crash NSD with an AXFR containing a DNS message with a special crafted SVCB RR with an rdata size of 65512, that let's an uint16t variable that is used to allocate space needed for the RR wrap because total size 65535,...

CVE-2026-12244 Heap overflow and crash with crafted SVCB RR

If NSD is configured as secondary for a zone, the primary of that zone can crash NSD with an AXFR containing a DNS message with a special crafted SVCB RR with an rdata size of 65512, that let's an uint16t variable that is used to allocate space needed for the RR wrap because total size 65535,...

CVE-2026-12244

NSD (the DNS server) is affected when configured as a secondary for a zone. A primary can crash NSD by sending an AXFR containing a DNS message with a specially crafted SVCB RR whose rdata size is 65512, which causes an (uint16_t) length to overflow while allocating space for the RR wrap (total s...

CVE-2026-12244 Heap overflow and crash with crafted SVCB RR

If NSD is configured as secondary for a zone, the primary of that zone can crash NSD with an AXFR containing a DNS message with a special crafted SVCB RR with an rdata size of 65512, that let's an uint16t variable that is used to allocate space needed for the RR wrap because total size 65535,...