PT-2025-24315 · Coredns · Coredns
Thevilledev
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Published
2025-06-06
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Updated
2026-05-21
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CVE-2025-47950
CVSS v2.0
7.8
High
| Vector | AV:N/AC:L/Au:N/C:N/I:N/A:C |
Name of the Vulnerable Software and Affected Versions
CoreDNS versions prior to 1.12.2
CoreDNS versions prior to 1.21.2
Description
A Denial of Service (DoS) issue 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 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.Recommendations
For versions prior to 1.12.2, update to version 1.12.2 or later.
For versions prior to 1.21.2, update to version 1.21.2 or later.
As a temporary workaround, consider disabling 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.
Monitor QUIC connection patterns and alert on anomalies.Exploit
Fix
DoS
Allocation of Resources Without Limits
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Weakness Enumeration
Related Identifiers
Affected Products
Coredns