Denial of Service Vulnerability in CoreDNS by Cloudflare
CVE-2026-26018

7.5HIGH

Key Information:

Vendor

Coredns

Status
Coredns
Vendor
CVE Published:
6 March 2026

What is CVE-2026-26018?

CoreDNS, a popular DNS server that supports plugin chaining, is susceptible to a denial of service vulnerability caused by its loop detection plugin. Attackers can exploit this flaw by sending specially crafted DNS queries that lead to server crashes. The issue arises from the reliance on a predictable pseudo-random number generator (PRNG) to create a secret query name. Additionally, the server's fatal error handler terminates the entire process in case of an error, amplifying the potential for service disruption. This vulnerability has been addressed in CoreDNS version 1.14.2.

Affected Version(s)

coredns < 1.14.2

References

https://github.com/coredns/coredns/security/advisories/GH...
x_refsource_CONFIRM
https://github.com/coredns/coredns/releases/tag/v1.14.2
x_refsource_MISC

CVSS V3.1

Score:
7.5
Severity:
HIGH
Confidentiality:
None
Integrity:
None
Availability:
None
Attack Vector:
Network
Attack Complexity:
Low
Privileges Required:
None
User Interaction:
None
Scope:
Unchanged

Timeline

  • Vulnerability published

  • Vulnerability Reserved

.