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
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).
- Lower severity and no public exploit yet
A fix is available — apply it.
- CVSS v3
- 6.3
- EG Score
- 6.3(low)
- EPSS
- 31.1%
- KEV
- Not listed
Published
March 6, 2026
Last Modified
July 15, 2026
Advisory Details (2)
Auto-updated Jul 9, 2026v1.14.2
Patch available: coredns/coredns v1.14.2
https://github.com/coredns/coredns/releases/tag/v1.14.2CoreDNS ACL Bypass · Advisory · coredns/coredns · GitHub
https://github.com/coredns/coredns/security/advisories/GHSA-c9v3-4pv7-87prVendor Advisories for CVE-2026-26017(4)
These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.
- RHSA-2026:36873Red Hat Product SecurityHigh
Red Hat Security Advisory: Submariner v0.20 security fixes and container updates
- 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 15× in last 7d / 47× 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.
- 2026-07-22 14:08 UTCEPSS rescore
- 2026-07-22 14:08 UTCEPSS rescore
- 2026-07-21 15:24 UTCEPSS rescore
- 2026-07-21 15:24 UTCEPSS rescore
- 2026-07-20 17:08 UTCEPSS rescore
- 2026-07-20 17:08 UTCEPSS rescore
- 2026-07-19 14:31 UTCEPSS rescore
- 2026-07-19 14:31 UTCEPSS rescore
- 2026-07-19 02:29 UTCEPSS rescore
- 2026-07-19 02:28 UTCEPSS rescore
- 2026-07-18 10:04 UTCEPSS rescore
- 2026-07-18 10:04 UTCEPSS rescore
- 2026-07-18 06:59 UTCOSV refresh
- 2026-07-16 17:03 UTCEPSS rescore
- 2026-07-16 17:03 UTCEPSS rescore
- 2026-07-15 16:57 UTCEPSS rescore
- 2026-07-15 16:57 UTCEPSS rescore
- 2026-07-15 02:22 UTCNVD updateCVSS v3 → 6.3 · severity → MEDIUM
- 2026-07-15 02:00 UTCEPSS rescore
- 2026-07-15 02:00 UTCEPSS rescore
- 2026-07-15 01:21 UTCMITRE cvelistV5CVSS v3 → 7.7 · severity → HIGH
- 2026-07-13 22:30 UTCEPSS rescore
- 2026-07-13 06:13 UTCEPSS rescore
- 2026-07-13 06:13 UTCEPSS rescore
- 2026-07-12 05:46 UTCEPSS rescore
Show 22 moreShow fewer
- 2026-07-12 05:46 UTCEPSS rescore
- 2026-07-11 08:27 UTCEPSS rescore
- 2026-07-09 19:10 UTCEPSS rescore
- 2026-07-09 13:52 UTCNVD updateCVSS v3 → 6.3 · severity → MEDIUM
- 2026-07-09 12:25 UTCMITRE cvelistV5CVSS v3 → 7.7 · severity → HIGH
- 2026-07-08 15:15 UTCEPSS rescore
- 2026-07-08 15:15 UTCEPSS rescore
- 2026-07-07 13:46 UTCEPSS rescore
- 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
Related CVEs(same vendor + same CWE)
Same vendor
10 shownredhat · msrc
Frequently asked(5)
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