CVE-2026-82399Public exploitNetwork attack vectorHinoki check available

Unauthenticated service termination via pre-validation allocation amplification

Published Sep 16, 2026 · Updated Sep 18, 2026

Resource exhaustion in CoreDNS before 1.14.7 allows remote attackers to terminate DNS service through crafted custom-transport requests. The DoH, DoH3, DoQ, and DNS-over-gRPC paths unpack compressed DNS sections using attacker-controlled counts before validating the fixed header, amplifying memory allocation. Exploitation requires exposure of one of those custom listeners; ordinary UDP and TCP listeners validate the header first and are not affected.

CVSS severity7.5
High
EPSS probability0.61%
Next 30 days · Oct 19, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
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Summary

What happened

Resource exhaustion in CoreDNS before 1.14.7 allows remote attackers to terminate DNS service through crafted custom-transport requests. The DoH, DoH3, DoQ, and DNS-over-gRPC paths unpack compressed DNS sections using attacker-controlled counts before validating the fixed header, amplifying memory allocation. Exploitation requires exposure of one of those custom listeners; ordinary UDP and TCP listeners validate the header first and are not affected.

The record

CVE
CVE-2026-82399
Published
Sep 16, 2026
Updated
Sep 18, 2026
Vendor
CoreDNS
Product
CoreDNS
Classifications
CWE-770, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Sep 16, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 18, 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=< 1.14.7

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

CoreDNS · CoreDNSversion=< 1.14.7

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.

Activity data is delayed. The latest report is Sep 28, 2026.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 22, 2026Sep 28, 2026
Latest reporting daySep 28, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-770Allocation of Resources Without Limits or Throttling
T1499.004Endpoint Denial of Service: Application or System Exploitation

Public exploit references

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Technologies

Your stack

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Your stack

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