CoreDNS ACL Bypass
Summary
| CVE | CVE-2026-26017 |
|---|---|
| State | PUBLISHED |
| Assigner | GitHub_M |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-03-06 16:16:10 UTC |
| Updated | 2026-07-15 02:18:59 UTC |
| Description | 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. |
Risk And Classification
Primary CVSS: v3.1 6.3 MEDIUM from [email protected]
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:N/A:N
EPSS: 0.003850000 probability, percentile 0.307510000 (date 2026-07-16)
Problem Types: CWE-367 | CWE-367 CWE-367: Time-of-check Time-of-use (TOCTOU) Race Condition | CWE-367 Time-of-check Time-of-use (TOCTOU) Race Condition
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 3.1 | [email protected] | Primary | 6.3 | MEDIUM | CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:N/A:N |
| 3.1 | ADP | CVSS | 7.7 | HIGH | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N |
| 3.1 | [email protected] | Secondary | 7.7 | HIGH | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N |
| 3.1 | 0b0ca135-0b70-47e7-9f44-1890c2a1c46c | Secondary | 7.7 | HIGH | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N |
| 3.1 | CNA | DECLARED | 7.7 | HIGH | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N |
CVSS v3.1 Breakdown
Attack Vector
NetworkAttack Complexity
HighPrivileges Required
LowUser Interaction
NoneScope
ChangedConfidentiality
HighIntegrity
NoneAvailability
NoneCVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:N/A:N
NVD Known Affected Configurations (CPE 2.3)
| Type | Vendor | Product | Version | Update | Edition | Language |
|---|---|---|---|---|---|---|
| Application | Coredns.io | Coredns | All | All | All | All |
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | Coredns | Coredns | affected < 1.14.2 | Not specified |
| ADP | Red Hat | Red Hat Advanced Cluster Management For Kubernetes 2.13 | unaffected 1782924920 * rpm | Not specified |
| ADP | Red Hat | Red Hat Advanced Cluster Management For Kubernetes 2.13 | unaffected 1782924937 * rpm | Not specified |
| ADP | Red Hat | Red Hat Advanced Cluster Management For Kubernetes 2.14 | unaffected 1780204232 * rpm | Not specified |
| ADP | Red Hat | Red Hat Advanced Cluster Management For Kubernetes 2.14 | unaffected 1780204249 * rpm | Not specified |
| ADP | Red Hat | Red Hat Advanced Cluster Management For Kubernetes 2.15 | unaffected 1774086225 * rpm | Not specified |
| ADP | Red Hat | Red Hat Connectivity Link 1 | Not specified | Not specified |
| ADP | Red Hat | Red Hat OpenShift Container Platform 4 | Not specified | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| github.com/coredns/coredns/security/advisories/GHSA-c9v3-4pv7-87pr | [email protected] | github.com | Mitigation, Vendor Advisory |
| access.redhat.com/security/cve/CVE-2026-26017 | 0b0ca135-0b70-47e7-9f44-1890c2a1c46c | access.redhat.com | |
| github.com/coredns/coredns/releases/tag/v1.14.2 | [email protected] | github.com | Product, Release Notes |
| access.redhat.com/errata/RHSA-2026:25127 | 0b0ca135-0b70-47e7-9f44-1890c2a1c46c | access.redhat.com | |
| access.redhat.com/errata/RHSA-2026:36873 | 0b0ca135-0b70-47e7-9f44-1890c2a1c46c | access.redhat.com | |
| access.redhat.com/errata/RHSA-2026:8151 | 0b0ca135-0b70-47e7-9f44-1890c2a1c46c | access.redhat.com | |
| security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-26017.json | 0b0ca135-0b70-47e7-9f44-1890c2a1c46c | security.access.redhat.com | |
| bugzilla.redhat.com/show_bug.cgi | 0b0ca135-0b70-47e7-9f44-1890c2a1c46c | bugzilla.redhat.com | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
No vendor comments have been submitted for this CVE.
Additional Advisory Data
| Source | Time | Event |
|---|---|---|
| ADP | 2026-03-06T16:01:45.971Z | Reported to Red Hat. |
| ADP | 2026-03-06T15:36:15.655Z | Made public. |
Solutions
ADP: RHSA-2026:36873: Red Hat Advanced Cluster Management for Kubernetes 2.13
ADP: RHSA-2026:25127: Red Hat Advanced Cluster Management for Kubernetes 2.14
ADP: RHSA-2026:8151: Red Hat Advanced Cluster Management for Kubernetes 2.15
Workarounds
ADP: Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.
There are currently no legacy QID mappings associated with this CVE.