What’s Vulnerable › Vulnerabilities

CVE-2026-26018: CoreDNS Loop Detection Denial of Service Vulnerability

• Severity: high (CVSS 7.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 1.2% probability of exploitation in the next 30 days
• Public exploit or detection template: yes
• Published: 2026-03-06 · updated 2026-07-15
• Weakness: CWE-337

Description

CoreDNS is a DNS server that chains plugins. Prior to version 1.14.2, a denial of service vulnerability exists in CoreDNS's loop detection plugin that allows an attacker to crash the DNS server by sending specially crafted DNS queries. The vulnerability stems from the use of a predictable pseudo-random number generator (PRNG) for generating a secret query name, combined with a fatal error handler that terminates the entire process. This issue has been patched in version 1.14.2.

Affected products

• coredns: before 1.14.2 — fixed in 1.14.2

How to fix

Upgrade to a fixed version: coredns 1.14.2. Check the vendor advisory for mitigations.

References

• https://github.com/coredns/coredns/releases/tag/v1.14.2
• https://github.com/coredns/coredns/security/advisories/GHSA-h75p-j8xm-m278
• https://access.redhat.com/errata/RHSA-2026:25127
• https://access.redhat.com/errata/RHSA-2026:36873
• https://access.redhat.com/errata/RHSA-2026:8151
• https://access.redhat.com/security/cve/CVE-2026-26018
• https://bugzilla.redhat.com/show_bug.cgi?id=2445242
• https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-26018.json

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