CVE - CVE-2025-47950

CVE-ID
CVE-2025-47950	Learn more at National Vulnerability Database (NVD) • CVSS Severity Rating • Fix Information • Vulnerable Software Versions • SCAP Mappings • CPE Information
Description
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.
References
Note: References are provided for the convenience of the reader to help distinguish between vulnerabilities. The list is not intended to be complete.
MISC:https://datatracker.ietf.org/doc/html/rfc9250 URL:https://datatracker.ietf.org/doc/html/rfc9250 MISC:https://github.com/coredns/coredns/commit/efaed02c6a480ec147b1f799aab7cf815b17dfe1 URL:https://github.com/coredns/coredns/commit/efaed02c6a480ec147b1f799aab7cf815b17dfe1 MISC:https://github.com/coredns/coredns/security/advisories/GHSA-cvx7-x8pj-x2gw URL:https://github.com/coredns/coredns/security/advisories/GHSA-cvx7-x8pj-x2gw MISC:https://github.com/quic-go/quic-go URL:https://github.com/quic-go/quic-go MISC:https://www.usenix.org/conference/usenixsecurity23/presentation/botella URL:https://www.usenix.org/conference/usenixsecurity23/presentation/botella
Assigning CNA
GitHub (maintainer security advisories)
Date Record Created
20250514	Disclaimer: The record creation date may reflect when the CVE ID was allocated or reserved, and does not necessarily indicate when this vulnerability was discovered, shared with the affected vendor, publicly disclosed, or updated in CVE.
Phase (Legacy)
Assigned (20250514)
Votes (Legacy)

Comments (Legacy)

Proposed (Legacy)
N/A
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