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.
CVE-2026-26017
MEDIUMNVD 6.36.3
EchelonGraph scoreLOW confidence
This medium-severity CVE scores 6.3 under NVD CVSS v3. EPSS exploit-prediction score not yet available (the EPSS model rescores nightly; freshly-published CVEs typically appear within 48 hours). GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).
Triggered by: NVD CVSS baseline
Sources: nvd
6.3
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
- Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS: 0%CVSS: 6.3Exploit: NoneExposed: 0
A fix is available — apply it.
- CVSS v3
- 6.3
- EG Score
- 6.3(low)
- EPSS
- 29.6%
- KEV
- Not listed
Published
March 6, 2026
Last Modified
June 30, 2026
References (7)
- security-advisories@githubhttps://github.com/coredns/coredns/releases/tag/v1.14.2
- security-advisories@githubhttps://github.com/coredns/coredns/security/advisories/GHSA-c9v3-4pv7-87pr
- 0b0ca135-0b70-47e7-9f44-1890c2a1c46chttps://access.redhat.com/errata/RHSA-2026:25127
- 0b0ca135-0b70-47e7-9f44-1890c2a1c46chttps://access.redhat.com/errata/RHSA-2026:8151
- 0b0ca135-0b70-47e7-9f44-1890c2a1c46chttps://access.redhat.com/security/cve/CVE-2026-26017
- 0b0ca135-0b70-47e7-9f44-1890c2a1c46chttps://bugzilla.redhat.com/show_bug.cgi?id=2445244
- 0b0ca135-0b70-47e7-9f44-1890c2a1c46chttps://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-26017.json
Vendor Advisories for CVE-2026-26017(3)
These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.
- RHSA-2026:25127Red Hat Product SecurityHigh
Red Hat Security Advisory: Submariner v0.21 security fixes and container updates
- CVE-2026-26017Microsoft Security Response Center (MSRC)High
CoreDNS ACL Bypass
- RHSA-2026:8151Red Hat Product SecurityHigh
Red Hat Security Advisory: Submariner v0.22 security fixes and container updates
Patch Availability(2)
| Vendor / Ecosystem | Fixed in / Patch | Released | Source |
|---|---|---|---|
| redhat | rhacm2/lighthouse-coredns-rhel9:1780204249 | 2026-06-10 | redhat |
| redhat | rhacm2/lighthouse-coredns-rhel9:1774086225 | 2026-04-14 | redhat |
Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.
Affected Packages
(1 across 1 ecosystem)
Go(1)
| Package | Vulnerable range | Fixed in | Dependents |
|---|---|---|---|
| github.com/coredns/coredns | — | 1.14.2 | — |
Weakness Classification(1)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Data Freshness Timeline
(refreshed 11× in last 7d / 14× in last 30d)
Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.
- 2026-07-06 16:27 UTCEPSS rescore
- 2026-07-06 16:27 UTCEPSS rescore
- 2026-07-06 02:23 UTCEPSS rescore
- 2026-07-06 02:23 UTCEPSS rescore
- 2026-07-05 02:30 UTCEPSS rescore
- 2026-07-04 06:31 UTCEPSS rescore
- 2026-07-04 06:31 UTCEPSS rescore
- 2026-07-01 15:06 UTCEPSS rescore
- 2026-07-01 15:06 UTCEPSS rescore
- 2026-06-30 23:22 UTCEPSS rescore
- 2026-06-30 23:22 UTCEPSS rescore
- 2026-06-30 04:40 UTCEG score recompute
- 2026-06-30 04:40 UTCVendor advisory
- 2026-06-30 04:31 UTCNVD updatefirst tracked
Frequently asked(5)
What is CVE-2026-26017?
CVE-2026-26017 is a medium vulnerability published on March 6, 2026. 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…
When was CVE-2026-26017 disclosed?
CVE-2026-26017 was first published in the National Vulnerability Database on March 6, 2026, with the most recent update on June 30, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-26017 actively exploited?
CVE-2026-26017 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 29.6% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-26017?
CVE-2026-26017 has a CVSS v3 base score of 6.3 (NVD). The EG score is currently aggregating — additional source signals are being incorporated as they become available..
How do I remediate CVE-2026-26017?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-26017, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.
Dependency Blast Radius
See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-26017
Is Your Infrastructure Affected by CVE-2026-26017?
EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.