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Fencer Vulns
high 7.5

CVE-2026-62309 json

CoreDNS: proxyproto plugin panics on PPv2 datagram with non-UDP transport — single 28-byte packet remote DoS

published 2026-07-16 3 mo ago modified 2026-07-22 3 mo ago also EUVD-2026-45019

cvss
7.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.7%
EPSS 0.7% chance of exploitation in 30 days, percentile 51%
public exploits
0
none known

Summary

CoreDNS is a DNS server written in Go. Prior to 1.14.4, a single 28-byte UDP datagram can crash the CoreDNS process when the proxyproto plugin is enabled because plugin/pkg/proxyproto/proxyproto.go PacketConn.ReadFrom handles a PROXY v2 header with non-UDP transport such as family byte 0x11, reassigns addr from a nil readFrom result after parseProxyProtocol errors, and calls addr.String() in the warning log before ServeDNS recovery applies. This issue is fixed in version 1.14.4.

Patch / fix

  • coredns.io coredns 1.14.4

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-62309 updated cvss 7.5

github.com/coredns/coredns: CoreDNS: Denial of Service via crafted UDP datagram with proxyproto plugin

  • Red Hat Connectivity Link 1 rhcl-1/coredns-rhel9 Red Hat OpenShift Container Platform 4 openshift4/ose-coredns-rhel9
    affected: workaround, no fix available
  • Red Hat Advanced Cluster Management for Kubernetes 2.17 rhacm2/lighthouse-coredns-rhel9 1788023940
    fixed: vendor fix RHSA-2026:63016
  • Red Hat Advanced Cluster Management for Kubernetes 2 rhacm2/lighthouse-agent-rhel9 Red Hat Advanced Cluster Management for Kubernetes 2.17 rhacm2/subctl-rhel9 1788105072, rhacm2/nettest-rhel9 1788166791, rhacm2/lighthouse-agent-rhel9 1788023916, rhacm2/submariner-gateway-rhel9 1788043964, rhacm2/submariner-rhel9-operator 1788073481, rhacm2/submariner-globalnet-rhel9 1788043961, +2 more Red Hat OpenShift Container Platform 4 openshift4/ose-coredns
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
yes
Technical impact
partial
Assessed
3 mo ago

Exploit prediction

0.66% chance of exploitation in the next 30 days, higher than 51% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • github.com https://github.com/coredns/coredns/security/advisories/GHSA-9rvv-m5g5-wc8r referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected products

  • coredns coredns

Classification

Weakness

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.