CVE-2026-32934
CoreDNS DNS-over-QUIC unbounded goroutine growth leads to denial of service
Description
CoreDNS is a DNS server that chains plugins. In versions prior to 1.14.3, the DNS-over-QUIC (DoQ) server can be driven into unbounded goroutine and memory growth by a remote client that opens many QUIC streams and sends only 1 byte per stream. When the worker pool is full, CoreDNS still spawns a goroutine per accepted stream to wait for a worker token. Additionally, active workers block indefinitely in io.ReadFull() with no per-stream read deadline, allowing an attacker to pin all workers by sending a single byte so the read blocks waiting for the second byte of the DoQ length prefix. This enables an unauthenticated remote attacker to cause memory exhaustion and OOM-kill. This issue has been fixed in version 1.14.3. No known workarounds exist.
INFO
Published Date :
May 5, 2026, 8:16 p.m.
Last Modified :
May 8, 2026, 4:03 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | HIGH | [email protected] | ||||
| CVSS 4.0 | HIGH | [email protected] |
Solution
- Update CoreDNS to version 1.14.3 or later.
- Monitor server resource usage.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-32934.
| URL | Resource |
|---|---|
| https://github.com/coredns/coredns/releases/tag/v1.14.3 | Release Notes |
| https://github.com/coredns/coredns/security/advisories/GHSA-2wpx-qpw2-g5h5 | Exploit Vendor Advisory |
| https://github.com/coredns/coredns/security/advisories/GHSA-2wpx-qpw2-g5h5 | Exploit Vendor Advisory |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-32934 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-32934
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-32934 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-32934 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
Initial Analysis by [email protected]
May. 08, 2026
Action Type Old Value New Value Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Added CPE Configuration OR *cpe:2.3:a:coredns.io:coredns:*:*:*:*:*:*:*:* versions up to (excluding) 1.14.3 Added Reference Type GitHub, Inc.: https://github.com/coredns/coredns/releases/tag/v1.14.3 Types: Release Notes Added Reference Type CISA-ADP: https://github.com/coredns/coredns/security/advisories/GHSA-2wpx-qpw2-g5h5 Types: Exploit, Vendor Advisory Added Reference Type GitHub, Inc.: https://github.com/coredns/coredns/security/advisories/GHSA-2wpx-qpw2-g5h5 Types: Exploit, Vendor Advisory -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
May. 06, 2026
Action Type Old Value New Value Added Reference https://github.com/coredns/coredns/security/advisories/GHSA-2wpx-qpw2-g5h5 -
New CVE Received by [email protected]
May. 05, 2026
Action Type Old Value New Value Added Description CoreDNS is a DNS server that chains plugins. In versions prior to 1.14.3, the DNS-over-QUIC (DoQ) server can be driven into unbounded goroutine and memory growth by a remote client that opens many QUIC streams and sends only 1 byte per stream. When the worker pool is full, CoreDNS still spawns a goroutine per accepted stream to wait for a worker token. Additionally, active workers block indefinitely in io.ReadFull() with no per-stream read deadline, allowing an attacker to pin all workers by sending a single byte so the read blocks waiting for the second byte of the DoQ length prefix. This enables an unauthenticated remote attacker to cause memory exhaustion and OOM-kill. This issue has been fixed in version 1.14.3. No known workarounds exist. Added CVSS V4.0 AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X Added CWE CWE-770 Added Reference https://github.com/coredns/coredns/releases/tag/v1.14.3 Added Reference https://github.com/coredns/coredns/security/advisories/GHSA-2wpx-qpw2-g5h5