CoreDNS Vulnerable to DoQ Memory Exhaustion via Stream Amplification

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

7.5 · CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

EPSS

• CVE-2025-47950: 1.19% estimated exploitation activity in the next 30 days; percentile 68.07 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Summary A 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. Impact - Component: serverquic.go - Attack Vector: Remote, network-based - Attack Complexity: Low - Privileges Required: None - User Interaction: None - Impact: High availability loss (OOM kill or unresponsiveness) This 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. Patches The patch introduces two key mitigation mechanisms: - maxstreams: Caps the number of…

Published by the source

6 Jun 2025, 21:27 UTC

Last modified by the source

9 Jun 2025, 21:39 UTC

Source last checked

26 Oct 2026, 15:09 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-cvx7-x8pj-x2gw

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# Patch Next advisory brief: CVE-2025-47950

Advisory: CoreDNS Vulnerable to DoQ Memory Exhaustion via Stream Amplification
IDs: CVE-2025-47950, GHSA-cvx7-x8pj-x2gw
Record: https://patchnext.com/advisories/cve-2025-47950 (revision 1, source checked 26 Oct 2026, 15:09 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: High (CVSS 7.5)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: github.com/coredns/coredns 1.12.2. A vendor fix does not mean a deployment is fixed.

## Affected components
- Go github.com/coredns/coredns: affected < 1.12.2; fixed in 1.12.2

## Suggested inspection (read-only)
- Go github.com/coredns/coredns: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on github.com/coredns/coredns.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-cvx7-x8pj-x2gw (GitHub-reviewed advisory GHSA-cvx7-x8pj-x2gw lists affected ranges: Go github.com/coredns/coredns >=0 <1.12.2)

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