CVE-2026-32936Public exploitNetwork attack vector

DoS via unbounded DoH GET decoding

Published May 5, 2026 · Updated May 5, 2026

Resource exhaustion in CoreDNS before 1.14.3 allows remote attackers to interrupt DoH service with oversized GET queries. The requestToMsgGet path parses the full query and passes its unbounded dns value to base64ToMsg, which decodes and unpacks it before rejection. No authentication or user interaction is required, but an HTTPS listener must be configured; repeated requests consume CPU and memory until service responsiveness or availability is lost.

CVSS severity7.5
High
EPSS probability0.67%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Resource exhaustion in CoreDNS before 1.14.3 allows remote attackers to interrupt DoH service with oversized GET queries. The requestToMsgGet path parses the full query and passes its unbounded dns value to base64ToMsg, which decodes and unpacks it before rejection. No authentication or user interaction is required, but an HTTPS listener must be configured; repeated requests consume CPU and memory until service responsiveness or availability is lost.

The record

CVE
CVE-2026-32936
Published
May 5, 2026
Updated
May 5, 2026
Vendor
CoreDNS
Product
CoreDNS
Classifications
CWE-400, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 5, 2026CVE publishedPublication date reported by the CVE source.
  2. May 5, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 1.14.3

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

CoreDNS · CoreDNSversion=< 1.14.3

Published CVSS scores

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

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-400Uncontrolled Resource Consumption
T1499.004Application or System Exploitation Flood

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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