CVE-2026-62309: CoreDNS is a DNS server written in Go

Q: How do I fix CVE-2026-62309?

coredns: upgrade to 1.14.4. Exact commands for each OS are on this page.

Q: Is CVE-2026-62309 being exploited?

CVE-2026-62309 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2026-62309 affect?

CVE-2026-62309 affects coredns. Severity is high (CVSS 7.5). 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 hea

Q: How urgent is CVE-2026-62309?

Priority 49/100. High severity; Public exploit reference; Remotely exploitable, no login, no user action

This week

HIGH 7.5REMOTEUPGRADE

CVE-2026-62309 is a high-severity flaw (CVSS 7.5) affecting coredns. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

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

Why this priority

High severity
Public exploit reference
Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	7.5 (High)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	0.7% (top 49%)
CISA exploited list	No
Weakness	CWE-476
Published	2026-07-16
Last modified	2026-07-22

Publisher (CNA): GitHub, Inc. · Vendor: coredns.io

Last updated 2026-07-22 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-07-16 20:16 UTCPublished CVE record published
2026-07-22 20:17 UTCUpdated Record last modified

coredns.io coredns UPGRADE

Affected: < 1.14.4

Fixed in: 1.14.4

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy coredns || rpm -q coredns || coredns --version

2. UPGRADE to 1.14.4 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade coredns

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade coredns

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-62309?

coredns: upgrade to 1.14.4. Exact commands for each OS are on this page.

Is CVE-2026-62309 being exploited?

CVE-2026-62309 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-62309 affect?

CVE-2026-62309 affects coredns. Severity is high (CVSS 7.5). 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 hea

How urgent is CVE-2026-62309?

Priority 49/100. High severity; Public exploit reference; Remotely exploitable, no login, no user action

Related CVEs

CVE-2026-62299 MEDIUM 5.3 UPGRADE CoreDNS is a DNS server written in Go
CVE-2026-62994 LOW 3.7 UPGRADE CoreDNS is a DNS server written in Go

References

← Back to latest CVEs