{"id":"CVE-2025-47950","aliases":["AZL-63678","AZL-63695","EUVD-2025-17359","GHSA-cvx7-x8pj-x2gw","GO-2025-3743","openSUSE-SU-2025:15225-1"],"status":"published","title":"CoreDNS Vulnerable to DoQ Memory Exhaustion via Stream Amplification","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.","severity":{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-09","score":0.01194,"percentile":0.68247,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-770"],"published":"2025-06-06T17:32:30Z","modified":"2026-11-05T05:40:51Z","fixes":[{"ecosystem":"Go","package":"github.com/coredns/coredns","fixed_in":["1.12.2"],"sources":["ghsa","osv"]},{"ecosystem":"Azure Linux:3","package":"coredns","fixed_in":["1.11.4-7"],"sources":["osv"]},{"ecosystem":"Azure Linux:2","package":"coredns","fixed_in":["1.11.1-19"],"sources":["osv"]}],"affected":[{"source":"ghsa","ecosystem":"Go","package":"github.com/coredns/coredns","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.12.2"}]}]},{"source":"osv","ecosystem":"Azure Linux:3","package":"coredns","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.11.4-7"}]}]},{"source":"osv","ecosystem":"Azure Linux:2","package":"coredns","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.11.1-19"}]}]},{"source":"osv","ecosystem":"Go","package":"github.com/coredns/coredns","ranges":[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"1.12.2"}]}]},{"source":"osv","ecosystem":"Go","package":"github.com/coredns/coredns","ranges":[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"1.12.2"}]}]},{"source":"osv","ecosystem":"openSUSE:Tumbleweed","package":"govulncheck-vulndb","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"0.0.20250612T141001-1.1"}]}],"bundled":29}],"products":[{"vendor":"coredns","product":"coredns"},{"vendor":"coredns.io","product":"coredns"}],"references":[{"url":"https://github.com/coredns/coredns/security/advisories/GHSA-cvx7-x8pj-x2gw","tags":["x_refsource_CONFIRM","Vendor Advisory","advisory","web"]},{"url":"https://github.com/coredns/coredns/commit/efaed02c6a480ec147b1f799aab7cf815b17dfe1","tags":["x_refsource_MISC","Patch","fix","web"]},{"url":"https://datatracker.ietf.org/doc/html/rfc9250","tags":["x_refsource_MISC","Technical Description","web"]},{"url":"https://github.com/quic-go/quic-go","tags":["x_refsource_MISC","Not Applicable","package","web"]},{"url":"https://www.usenix.org/conference/usenixsecurity23/presentation/botella","tags":["x_refsource_MISC","Broken Link","web"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2025-47950","tags":["web","advisory"]},{"url":"https://github.com/advisories/GHSA-cvx7-x8pj-x2gw"},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/47xxx/CVE-2025-47950.json","tags":["advisory"]},{"url":"https://github.com/coredns/coredns","tags":["package"]},{"url":"","tags":["advisory"]},{"url":"https://www.suse.com/security/cve/CVE-2020-36846","tags":["web"]},{"url":"https://www.suse.com/security/cve/CVE-2022-31022","tags":["web"]},{"url":"https://www.suse.com/security/cve/CVE-2023-42818","tags":["web"]},{"url":"https://www.suse.com/security/cve/CVE-2025-0913","tags":["web"]},{"url":"https://www.suse.com/security/cve/CVE-2025-1792","tags":["web"]},{"url":"https://www.suse.com/security/cve/CVE-2025-22874","tags":["web"]},{"url":"https://www.suse.com/security/cve/CVE-2025-25207","tags":["web"]},{"url":"https://www.suse.com/security/cve/CVE-2025-25208","tags":["web"]},{"url":"https://www.suse.com/security/cve/CVE-2025-2571","tags":["web"]},{"url":"https://www.suse.com/security/cve/CVE-2025-29785","tags":["web"]},{"url":"https://www.suse.com/security/cve/CVE-2025-3230","tags":["web"]},{"url":"https://www.suse.com/security/cve/CVE-2025-3260","tags":["web"]},{"url":"https://www.suse.com/security/cve/CVE-2025-3454","tags":["web"]},{"url":"https://www.suse.com/security/cve/CVE-2025-3611","tags":["web"]},{"url":"https://www.suse.com/security/cve/CVE-2025-3913","tags":["web"]},{"url":"https://www.suse.com/security/cve/CVE-2025-4128","tags":["web"]},{"url":"https://www.suse.com/security/cve/CVE-2025-4573","tags":["web"]},{"url":"https://www.suse.com/security/cve/CVE-2025-4673","tags":["web"]},{"url":"https://www.suse.com/security/cve/CVE-2025-47950","tags":["web"]},{"url":"https://www.suse.com/security/cve/CVE-2025-48494","tags":["web"]},{"url":"https://www.suse.com/security/cve/CVE-2025-48495","tags":["web"]},{"url":"https://www.suse.com/security/cve/CVE-2025-48710","tags":["web"]},{"url":"https://www.suse.com/security/cve/CVE-2025-48865","tags":["web"]},{"url":"https://www.suse.com/security/cve/CVE-2025-48938","tags":["web"]},{"url":"https://www.suse.com/security/cve/CVE-2025-48948","tags":["web"]},{"url":"https://www.suse.com/security/cve/CVE-2025-48949","tags":["web"]},{"url":"https://www.suse.com/security/cve/CVE-2025-49011","tags":["web"]},{"url":"https://www.suse.com/security/cve/CVE-2025-49136","tags":["web"]},{"url":"https://www.suse.com/security/cve/CVE-2025-49140","tags":["web"]}],"sources":{"cve":[{"id":"CVE-2025-47950","title":"CoreDNS Vulnerable to DoQ Memory Exhaustion via Stream Amplification","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.","status":"published","published":"2025-06-06T17:32:30.218Z","modified":"2025-06-06T21:27:05.841Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high","assessor":"cna"}],"cwes":["CWE-770"],"updated_at":"2026-11-02T14:32:25.982948Z"}],"euvd":[{"id":"EUVD-2025-17359","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.","status":"published","published":"2025-06-06T17:32:30Z","modified":"2025-06-06T21:27:05Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high"}],"updated_at":"2026-11-02T20:32:28.158705Z"}],"ghsa":[{"id":"GHSA-cvx7-x8pj-x2gw","title":"CoreDNS Vulnerable to DoQ Memory Exhaustion via Stream Amplification","description":"### Summary\n\nA **Denial of Service (DoS)** vulnerability was discovered 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.\n\n### Impact\n\n- **Component**: `server_quic.go`\n- **Attack Vector**: Remote, network-based\n- **Attack Complexity**: Low\n- **Privileges Required**: None\n- **User Interaction**: None\n- **Impact**: High availability loss (OOM kill or unresponsiveness)\n\nThis issue affects deployments with `quic://` enabled in the Corefile. A single attacker can cause the CoreDNS instance to become unresponsive using minimal bandwidth and CPU.\n\n### Patches\n\nThe patch introduces two key mitigation mechanisms:\n\n- **`max_streams`**: Caps the number of concurrent QUIC streams per connection. Default: `256`.\n- **`worker_pool_size`**: Introduces a server-wide, bounded worker pool to process incoming streams. Default: `1024`.\n\nThis eliminates the 1:1 stream-to-goroutine model and ensures that CoreDNS remains resilient under high concurrency. The new configuration options are exposed through the `quic` Corefile block:\n\n```\nquic {\n    max_streams 256\n    worker_pool_size 1024\n}\n```\n\nThese defaults are generous and aligned with typical DNS-over-QUIC client behavior.\n\n### Workarounds\n\nIf you're unable to upgrade immediately, you can:\n- Disable QUIC support by removing or commenting out the `quic://` block in your Corefile\n- Use container runtime resource limits to detect and isolate excessive memory usage\n- Monitor QUIC connection patterns and alert on anomalies\n\n### References\n\n- [RFC 9250 - DNS over Dedicated QUIC Connections](https://datatracker.ietf.org/doc/html/rfc9250)\n- [quic-go GitHub project](https://github.com/quic-go/quic-go)\n- [QUIC stream exhaustion class of vulnerabilities (related)](https://www.usenix.org/conference/usenixsecurity23/presentation/botella)\n\n### Credit\n\nThanks to [@thevilledev](https://github.com/thevilledev) for disclovering this vulnerability and contributing a high-quality fix.\n\n### For more information\n\nPlease consult our [security guide](https://github.com/coredns/coredns/blob/master/.github/SECURITY.md) for more information regarding our security process.","status":"published","published":"2025-06-06T21:27:27Z","modified":"2025-06-09T21:39:34Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high"}],"cwes":["CWE-770"],"updated_at":"2026-11-02T14:38:46.901955Z"}],"nvd":[{"id":"CVE-2025-47950","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.","status":"published","published":"2025-06-06T18:15:35.33Z","modified":"2026-06-17T09:28:53.323Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high","assessor":"secondary"}],"cwes":["CWE-770"],"updated_at":"2026-11-02T14:11:11.4244Z"}],"osv":[{"id":"CVE-2025-47950","title":"CoreDNS Vulnerable to DoQ Memory Exhaustion via Stream Amplification","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.","status":"published","published":"2025-06-06T17:32:30.218Z","modified":"2026-10-28T02:30:54.143601048Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high"}],"cwes":["CWE-770"],"updated_at":"2026-11-02T15:44:50.037003Z"},{"id":"GHSA-cvx7-x8pj-x2gw","title":"CoreDNS Vulnerable to DoQ Memory Exhaustion via Stream Amplification","description":"### Summary\n\nA **Denial of Service (DoS)** vulnerability was discovered 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.\n\n### Impact\n\n- **Component**: `server_quic.go`\n- **Attack Vector**: Remote, network-based\n- **Attack Complexity**: Low\n- **Privileges Required**: None\n- **User Interaction**: None\n- **Impact**: High availability loss (OOM kill or unresponsiveness)\n\nThis issue affects deployments with `quic://` enabled in the Corefile. A single attacker can cause the CoreDNS instance to become unresponsive using minimal bandwidth and CPU.\n\n### Patches\n\nThe patch introduces two key mitigation mechanisms:\n\n- **`max_streams`**: Caps the number of concurrent QUIC streams per connection. Default: `256`.\n- **`worker_pool_size`**: Introduces a server-wide, bounded worker pool to process incoming streams. Default: `1024`.\n\nThis eliminates the 1:1 stream-to-goroutine model and ensures that CoreDNS remains resilient under high concurrency. The new configuration options are exposed through the `quic` Corefile block:\n\n```\nquic {\n    max_streams 256\n    worker_pool_size 1024\n}\n```\n\nThese defaults are generous and aligned with typical DNS-over-QUIC client behavior.\n\n### Workarounds\n\nIf you're unable to upgrade immediately, you can:\n- Disable QUIC support by removing or commenting out the `quic://` block in your Corefile\n- Use container runtime resource limits to detect and isolate excessive memory usage\n- Monitor QUIC connection patterns and alert on anomalies\n\n### References\n\n- [RFC 9250 - DNS over Dedicated QUIC Connections](https://datatracker.ietf.org/doc/html/rfc9250)\n- [quic-go GitHub project](https://github.com/quic-go/quic-go)\n- [QUIC stream exhaustion class of vulnerabilities (related)](https://www.usenix.org/conference/usenixsecurity23/presentation/botella)\n\n### Credit\n\nThanks to [@thevilledev](https://github.com/thevilledev) for disclovering this vulnerability and contributing a high-quality fix.\n\n### For more information\n\nPlease consult our [security guide](https://github.com/coredns/coredns/blob/master/.github/SECURITY.md) for more information regarding our security process.","status":"published","published":"2025-06-06T21:27:27Z","modified":"2026-09-10T03:50:25.142827387Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high"}],"cwes":["CWE-770"],"updated_at":"2026-11-02T15:46:45.639885Z"},{"id":"AZL-63678","title":"CVE-2025-47950 affecting package coredns for versions less than 1.11.4-7","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.","status":"published","published":"2025-06-06T18:15:35Z","modified":"2026-11-05T05:40:51Z","updated_at":"2026-11-05T16:41:21.518778Z"},{"id":"AZL-63695","title":"CVE-2025-47950 affecting package coredns for versions less than 1.11.1-19","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.","status":"published","published":"2025-06-06T18:15:35Z","modified":"2026-04-21T04:32:12.276531Z","updated_at":"2026-11-02T15:28:07.805289Z"},{"id":"GO-2025-3743","title":"CoreDNS Vulnerable to DoQ Memory Exhaustion via Stream Amplification in github.com/coredns/coredns","description":"CoreDNS Vulnerable to DoQ Memory Exhaustion via Stream Amplification in github.com/coredns/coredns","status":"published","published":"2025-06-10T17:17:52Z","modified":"2026-02-04T04:20:59.286257Z","updated_at":"2026-11-02T15:47:01.728182Z"},{"id":"openSUSE-SU-2025:15225-1","title":"govulncheck-vulndb-0.0.20250612T141001-1.1 on GA media","description":"These are all security issues fixed in the govulncheck-vulndb-0.0.20250612T141001-1.1 package on the GA media of openSUSE Tumbleweed.","status":"published","published":"2025-07-03T00:00:00Z","modified":"2026-03-23T04:53:30.823164Z","updated_at":"2026-11-02T16:58:37.399567Z"}]}}