CVE-2025-68151 — coredns
Fix: coredns/coredns@0d8cbb1CVE-2025-68151 is a CWE-770 vulnerability in github.com/coredns/coredns. A fix is available for github.com/coredns/coredns — see the affected versions and patch details below.
CoreDNS gRPC/HTTPS/HTTP3 servers lack resource limits, enabling DoS via unbounded connections and oversized messages
Exploitation Status
No confirmed exploitation observed yet
- CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for CVE-2025-68151.
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
Real-World Exposure
github.com/coredns/corednsReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Go packages — download data is not available via public APIs for these ecosystems.
Description
Multiple CoreDNS server implementations (gRPC, HTTPS, and HTTP/3) lack critical resource-limiting controls. An unauthenticated remote attacker can exhaust memory and degrade or crash the server by opening many concurrent connections, streams, or sending oversized request bodies. The issue is similar in nature to CVE-2025-47950 (QUIC DoS) but affects additional server types that do not enforce connection limits, stream limits, or message size constraints.
Impact
1. Missing connection and stream limits (gRPC / HTTPS / HTTP3)
The affected servers do not enforce reasonable upper bounds on concurrent connections or active streams. An attacker can:
- Open many parallel connections
- Rapidly issue requests without limit
- Consume memory until the CoreDNS process becomes unresponsive or is terminated by the OOM killer
Testing demonstrates that modest resource configurations (e.g., 256 MB RAM) can be exhausted quickly. Increasing concurrency parameters in the PoCs allows attackers to scale the impact.
2. Missing message-size validation in the gRPC server
The gRPC server accepts arbitrarily large protobuf messages (default limit ~4 MB per request) without validating against DNS protocol constraints (maximum 64 KB). Sending multiple concurrent oversized messages can quickly exhaust available memory.
This vulnerability mirrors earlier hardening work in PR https://github.com/coredns/coredns/pull/7490, which applied checks for upstream proxying but left server-side request validation unprotected.
Result:
In all cases, remote unauthenticated attackers can reliably trigger memory exhaustion and cause a denial of service.
Patches
v1.14.0
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐹Go | github.com/coredns/coredns | all versions | 1.14.0go get github.com/coredns/coredns@v1.14.0 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/coredns/coredns, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update github.com/coredns/coredns to 1.14.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2025-68151 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2025-68151 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2025-68151. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Fixing This On Your OS
If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.
| Product | Fixed in | Advisory |
|---|---|---|
| Red Hat Advanced Cluster Management for Kubernetes 2.13 | rhacm2/lighthouse-agent-rhel9:1782924920 | RHSA-2026:36873 |
| Red Hat Advanced Cluster Management for Kubernetes 2.14 | rhacm2/lighthouse-coredns-rhel9:1780204249 | RHSA-2026:25127 |
| Red Hat Advanced Cluster Management for Kubernetes 2.15 | rhacm2/lighthouse-coredns-rhel9:1774086225 | RHSA-2026:8151 |
Frequently Asked Questions
Is CVE-2025-68151 in your dependencies?
O3 Security finds CVE-2025-68151 across Go dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.