Coredns.io: >> Coredns >> 1.5.0 Security Vulnerabilities
CoreDNS is a DNS server that chains plugins. Prior to version 1.14.0, multiple CoreDNS server implementations (gRPC, HTTPS, and HTTP/3) lack critical resource-limiting controls. An unauthenticated remote attacker can exhaust memory and degrade or crash the server by opening many concurrent connections, streams, or sending oversized request bodies. The issue is similar in nature to CVE-2025-47950 (QUIC DoS) but affects additional server types that do not enforce connection limits, stream limits, or message size constraints. Version 1.14.0 contains a patch.
CVSS Score
7.5
EPSS Score
0.001
Published
2026-01-08
CoreDNS is a DNS server that chains plugins. In versions prior to 1.12.2, a Denial of Service (DoS) vulnerability exists in the CoreDNS DNS-over-QUIC (DoQ) server implementation. The server previously created a new goroutine for every incoming QUIC stream without imposing any limits on the number of concurrent streams or goroutines. A remote, unauthenticated attacker could open a large number of streams, leading to uncontrolled memory consumption and eventually causing an Out Of Memory (OOM) crash — especially in containerized or memory-constrained environments. The patch in version 1.12.2 introduces two key mitigation mechanisms: `max_streams`, which caps the number of concurrent QUIC streams per connection with a default value of `256`; and `worker_pool_size`, which Introduces a server-wide, bounded worker pool to process incoming streams with a default value of `1024`. This eliminates the 1:1 stream-to-goroutine model and ensures that CoreDNS remains resilient under high concurrency. Some workarounds are available for those who are unable to upgrade. Disable QUIC support by removing or commenting out the `quic://` block in the Corefile, use container runtime resource limits to detect and isolate excessive memory usage, and/or monitor QUIC connection patterns and alert on anomalies.
CVSS Score
7.5
EPSS Score
0.001
Published
2025-06-06
CoreDNS through 1.10.1 enables attackers to achieve DNS cache poisoning and inject fake responses via a birthday attack.
CVSS Score
7.5
EPSS Score
0.001
Published
2024-09-18
An issue was discovered in CoreDNS through 1.10.1. There is a vulnerability in DNS resolving software, which triggers a resolver to ignore valid responses, thus causing denial of service for normal resolution. In an exploit, the attacker could just forge a response targeting the source port of a vulnerable resolver without the need to guess the correct TXID.
CVSS Score
7.5
EPSS Score
0.0
Published
2024-09-18