CVE-2025-479507.5HighCWE-770

CVE-2025-47950: CoreDNS Vulnerable to DoQ Memory Exhaustion via Stream Amplification

coredns

Affected: coredns · Exploitation: possible (1 to 10%)

Not in CyberSIXT coverage yet: no article names this CVE. This page shows the public record.

1.2%probability of exploitation in the next 30 days

68th percentile

050100

Higher than 68% of scored CVEs

7.5HighCVSS 3.1

LowMediumHighCrit.

DescriptionCVE.org

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.

Affected products1

From the CVE record. A product or version that is not listed is unknown, not unaffected.

coredns · coredns< 1.12.2

On the Atlas

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Open the Atlas

Exploitation: Possible (1 to 10%). EPSS between 1% and 10%.
CISA KEV: Not listed
Public check: No public nuclei template
Weakness: Allocation Without Limits · Denial of Service
Vendor: coredns
Published: June 2025
Band: Possible (1 to 10%), June 2025

CoverageNo articles yet

No CyberSIXT article names CVE-2025-47950 yet, so there is no coverage timeline, action brief or change log for it. Everything on this page comes from the public CVE record, CISA KEV, EPSS and the nuclei template index. Search the archive or see the CVEs in the news.