Bug 2445244 (CVE-2026-26017)

Summary: CVE-2026-26017 github.com/coredns/coredns: CoreDNS: DNS access control bypass due to plugin execution order flaw
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
Severity: high Docs Contact:
Priority: high    
Version: unspecifiedCC: alcohan, gparvin, jbalunas, pahickey, rhaigner
Target Milestone: ---Keywords: Security
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Hardware: All   
OS: Linux   
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A flaw was found in CoreDNS, a DNS server that uses a chain of plugins. This logical vulnerability allows an attacker to bypass DNS access controls. The issue occurs because security plugins, such as 'acl', are evaluated before the 'rewrite' plugin, creating a Time-of-Check Time-of-Use (TOCTOU) flaw. This flaw enables an attacker to circumvent intended access restrictions.
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
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Description OSIDB Bzimport 2026-03-06 16:02:09 UTC
CoreDNS is a DNS server that chains plugins. Prior to version 1.14.2, a logical vulnerability in CoreDNS allows DNS access controls to be bypassed due to the default execution order of plugins. Security plugins such as acl are evaluated before the rewrite plugin, resulting in a Time-of-Check Time-of-Use (TOCTOU) flaw. This issue has been patched in version 1.14.2.