7.5

CVE-2026-82399: CoreDNS: Unauthenticated memory exhaustion in custom transports

Awaiting analysis
AliasesCGA-4p78-93rw-qmh7CGA-6gcq-9q35-29mwCGA-p7p5-j4xw-hqpx
Published 16-09-2026Last modified 18-09-2026

Vulnerability summary

CVE-2026-82399 is a high (CVSS 7.5) vulnerability in coredns. EPSS estimates a 0.61% chance of exploitation in the next 30 days, higher than 49.2% of scored vulnerabilities.

Priority
Prioritisesevere

Severe, CVSS 7.5 (CVE.org); no exploitation reported by the 5 checked sources; EPSS 1% (FIRST, 03-11-2026)

Source freshness unavailable

How is this decided?
CVSS score
7.5/10
010
High · v3.1 (CVE.org)
EPSS score
0.61%
0%100%
Low · 0.00 pp in 30 days
KEVNot listedNot listed by any tracked catalog.
RansomwareNot flaggedNo ransomware use recorded.
Public exploits0No public exploits recorded

Timeline

  1. 16-09-2026
    PublishedVulnerability first disclosed.
  2. 18-09-2026
    Last modifiedVulnerability information updated.

Description

CoreDNS is a DNS server written in Go. Prior to 1.14.7, the DNS-over-HTTPS, DNS-over-HTTP/3, DNS-over-QUIC, and DNS-over-gRPC request paths in plugin/pkg/doh/doh.go, core/dnsserver/server_quic.go, and core/dnsserver/server_grpc.go call dns.Msg.Unpack on attacker-controlled DNS section counts before dns.DefaultMsgAcceptFunc validates the fixed header. An unauthenticated client can use DNS name compression and excessive section counts to amplify allocation before the plugin chain, so plugin-level rate limiting cannot prevent concurrent requests from exhausting memory and terminating CoreDNS. The ordinary UDP and TCP listeners are not affected because they validate the header first. This issue is fixed in version 1.14.7.

CVSS metrics

5 scores · 5 sources · 1 version

EPSS trend

Probability

0.61%

Chance of exploitation in the next 30 days

Percentile

49%

Versus all other CVEs

30-day change

No change 0.00 pp

From 0.61% on 04-10-2026

04-10-202603-11-2026

Known exploited

Compare KEV catalogs
CISA KEV

Not in the CISA KEV catalog.

ENISA CNW

Not in the ENISA CNW catalog.

CIRCL

Not in the CIRCL catalog.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Version check

Known conditions: network-reachable, no authentication, no user interaction (CVSS vector). Other conditions: not stated in public data.

Chainguard21 products
  • eks-distro-coredns-1.31< 1.31.47-r12
  • eks-distro-coredns-1.32< 1.32.40-r9
  • eks-distro-coredns-1.33< 1.33.30-r9
  • eks-distro-coredns-1.34< 1.34.21-r9
  • eks-distro-coredns-1.35< 1.35.12-r9
Wolfi3 products
  • juicefs-1.3< 1.3.3-r8
  • k8s_gateway< 1.8.2-r11
  • kubernetes-dns-node-cache< 1.26.8-r20
Coredns1 product
Github.com/coredns1 product
  • coredns< 1.14.7

4 vendors · 26 products

References

6 links