GHSA-cvx7-x8pj-x2gw · Severity: high · Ecosystem: go — CoreDNS Vulnerable to DoQ Memory Exhaustion via Stream Amplification
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.
Conclusion & alert: CVE-2025-47950 is rated Moderate Risk (42.7/100): CVSS High severity, with low exploitation likelihood (EPSS 0.15%). Mandatory action: Review affected assets and schedule remediation.
Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.
EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).
| # | Date | Old EPSS score | New EPSS score | Delta (New - Old) |
|---|---|---|---|---|
| 1 | 2026-04-02 | 0.05% | 0.15% | +0.10% |
| 2 | 2026-01-18 | 0.16% | 0.05% | -0.11% |
| 3 | 2025-11-23 | — | 0.16% | — |
Full EPSS history (9 records total)
CVSS metrics for this CVE.
| Base score | Version | Severity | Vector | Exploitability | Impact | Score source |
|---|---|---|---|---|---|---|
| 7.5 | 3.1 | HIGH |
|
3.9 | 3.6 | [email protected] |
GHSA-cvx7-x8pj-x2gw · Severity: high · Ecosystem: go — CoreDNS Vulnerable to DoQ Memory Exhaustion via Stream Amplification
| vendor | priority | summary | link |
|---|---|---|---|
alpine
|
— | CVE-2025-47950: 1 source package rows (coredns); 16 state rows across 2 repos (3.22-community, edge-community); fixed 0, open 16. | https://security.alpinelinux.org/vuln/CVE-2025-47950 |
redhat
|
medium | — | https://access.redhat.com/security/cve/CVE-2025-47950 |
suse
|
medium | CVE-2025-47950 severity moderate: SUSE including 37 source package names (govulncheck-vulndb-0.0.20250612T141001-1.1, govulncheck-vulndb-0.0.20250814T182633-160000.1.2, …), 38 product×package rows across 5 product lines (Container suse/sl-micro/6.0/baremetal-os-container, Image SLE-Micro-Azure, … (5 product lines)): Fixed 38. | https://www.suse.com/security/cve/CVE-2025-47950/ |
| Vendor | Product | Version | Raw CPE |
|---|---|---|---|
| coredns.io | coredns | < 1.12.2 | cpe:2.3:a:coredns.io:coredns:*:*:*:*:*:*:*:* |
| URL | Tags |
|---|---|
| https://datatracker.ietf.org/doc/html/rfc9250 | Technical Description |
| https://github.com/coredns/coredns/commit/efaed02c6a480ec147b1f799aab7cf815b17dfe1 | Patch |
| https://github.com/coredns/coredns/security/advisories/GHSA-cvx7-x8pj-x2gw | Vendor Advisory |
| https://github.com/quic-go/quic-go | Not Applicable |
| https://www.usenix.org/conference/usenixsecurity23/presentation/botella | Broken Link |