Missing Critical Step in Authentication

Overview github.com/coredns/coredns/core/dnsserver is a package that implements all the interfaces from Caddy, so that CoreDNS can be a servertype plugin. Affected versions of this package are vulnerable to Missing Critical Step in Authentication in the TSIG authentication process for gRPC, QUIC,...

CoreDNS has TSIG authentication bypass on gRPC and QUIC transports

Summary The gRPC, QUIC, DoH, and DoH3 transports in CoreDNS incorrectly handle TSIG authentication. For gRPC and QUIC, CoreDNS checks whether the TSIG key name exists in the config, but does not actually verify the TSIG HMAC. If the key name matches, tsigStatus remains nil and the tsig plugin...

GHSA-VP29-5652-4FW9 CoreDNS has TSIG authentication bypass on gRPC and QUIC transports

Summary The gRPC, QUIC, DoH, and DoH3 transports in CoreDNS incorrectly handle TSIG authentication. For gRPC and QUIC, CoreDNS checks whether the TSIG key name exists in the config, but does not actually verify the TSIG HMAC. If the key name matches, tsigStatus remains nil and the tsig plugin...

Missing Authentication for Critical Function

Overview github.com/coredns/coredns/core/dnsserver is a package that implements all the interfaces from Caddy, so that CoreDNS can be a servertype plugin. Affected versions of this package are vulnerable to Missing Authentication for Critical Function via the tsig plugin on non-plain-DNS...

CoreDNS has TSIG authentication bypass on DoT, DoH, DoH3, DoQ, and gRPC

Summary CoreDNS' tsig plugin can be bypassed on non-plain-DNS transports because it trusts the transport writer's TsigStatus instead of performing verification itself. In the attached PoC, plain DNS/TCP correctly rejects an invalid TSIG NOTAUTH, while the same invalid-TSIG request is accepted ove...

GHSA-QHMP-Q7XH-99RH CoreDNS has TSIG authentication bypass on DoT, DoH, DoH3, DoQ, and gRPC

Summary CoreDNS' tsig plugin can be bypassed on non-plain-DNS transports because it trusts the transport writer's TsigStatus instead of performing verification itself. In the attached PoC, plain DNS/TCP correctly rejects an invalid TSIG NOTAUTH, while the same invalid-TSIG request is accepted ove...

Missing Authorization

Overview Affected versions of this package are vulnerable to Missing Authorization due to improper access control in the transfer process. An attacker can retrieve unauthorized zone contents by exploiting the incorrect selection of access control list stanzas when both parent and subzone rules ar...

CoreDNS DoH GET oversized dns= query parameter causes pre-validation CPU and memory amplification

Summary CoreDNS's DNS-over-HTTPS DoH GET path accepts oversized dns= query values and performs substantial request parsing, query unescaping, base64 decoding, and message unpacking work before returning 400 Bad Request. A remote, unauthenticated attacker can repeatedly send oversized DoH GET...

Allocation of Resources Without Limits or Throttling

Overview Affected versions of this package are vulnerable to Allocation of Resources Without Limits or Throttling through the requestToMsgGet process. An attacker can exhaust CPU and memory resources by sending oversized DNS-over-HTTPS GET requests with large dns query parameters, causing the...

Allocation of Resources Without Limits or Throttling

Overview github.com/coredns/coredns/core/dnsserver is a package that implements all the interfaces from Caddy, so that CoreDNS can be a servertype plugin. Affected versions of this package are vulnerable to Allocation of Resources Without Limits or Throttling through the DoQ server's handling of...

GHSA-2WPX-QPW2-G5H5 CoreDNS' DoQ worker pool does not bound stream backlog

Summary CoreDNS' DNS-over-QUIC DoQ server can be driven into large goroutine and memory growth by a remote client that opens many QUIC streams and stalls after sending only 1 byte. Even with a small configured quic workerpoolsize ... , CoreDNS still spawns a goroutine per accepted stream workers ...

CoreDNS' DoQ worker pool does not bound stream backlog

Summary CoreDNS' DNS-over-QUIC DoQ server can be driven into large goroutine and memory growth by a remote client that opens many QUIC streams and stalls after sending only 1 byte. Even with a small configured quic workerpoolsize ... , CoreDNS still spawns a goroutine per accepted stream workers ...

AZL-85004 CVE-2026-6238 affecting package glibc 2.38-20

The deprecated functions nsprintrrf, nsprintrr and fpnquery in the GNU C Library version 2.0.1 to version 2.43 fail to validate the RDATA content against the RDATA length in a DNS response when processing A6, CERT, LOC, TKEY or TSIG records, which may allow an attacker to craft a DNS response,...

CVE-2026-41393

OpenClaw before 2026.3.31 contains a wide-area discovery vulnerability allowing arbitrary tailnet peers to be accepted as DNS authorities. Attackers with same-tailnet position and CA-trusted endpoint access can exfiltrate operator credentials through DNS steering manipulation...

EUVD-2026-26071

The deprecated functions nsprintrrf, nsprintrr and fpnquery in the GNU C Library version 2.2 and newer fail to validate the RDATA content against the RDATA length in a DNS response when processing LOC, CERT, TKEY or TSIG records, which may allow an attacker to craft a DNS response, causing a targ...

CVE-2026-6238

The deprecated functions nsprintrrf, nsprintrr and fpnquery in the GNU C Library version 2.0.1 to version 2.43 fail to validate the RDATA content against the RDATA length in a DNS response when processing A6, CERT, LOC, TKEY or TSIG records, which may allow an attacker to craft a DNS response,...

CVE-2026-6238 Buffer overread in ns_printrrf with corrupted RDATA field

The deprecated functions nsprintrrf, nsprintrr and fpnquery in the GNU C Library version 2.0.1 to version 2.43 fail to validate the RDATA content against the RDATA length in a DNS response when processing A6, CERT, LOC, TKEY or TSIG records, which may allow an attacker to craft a DNS response,...

CVE-2026-6238

The deprecated functions nsprintrrf, nsprintrr and fpnquery in the GNU C Library version 2.0.1 to version 2.43 fail to validate the RDATA content against the RDATA length in a DNS response when processing A6, CERT, LOC, TKEY or TSIG records, which may allow an attacker to craft a DNS response,...

CVE-2026-6238

GLIBC: The deprecated debugging functions ns_printrrf, ns_printrr and fp_nquery in GNU C Library (glibc) 2.2 and newer fail to validate RDATA against its length for DNS LOC, CERT, TKEY or TSIG records. This may let an attacker craft a DNS response that crashes a target application or reads uninit...

CVE-2026-5435 Potential buffer overflow in ns_sprintrrf TSIG handling path

The deprecated functions nsprintrrf, nsprintrr and fpnquery in the GNU C Library version 2.2 and newer fail to enforce the caller-supplied buffer length, and can result in an out-of-bounds write when printing TSIG records...