How severe is CVE-2026-26017?

CVE-2026-26017 has a CVSS 3.x base score of 7.7, rated high severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.

Is CVE-2026-26017 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (30th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-26017?

CVE-2026-26017 affects Coredns.io Coredns. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-26017?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

Does CVE-2026-26017 have an EU (EUVD) identifier?

Yes. CVE-2026-26017 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-10042.

When was CVE-2026-26017 published?

CVE-2026-26017 was published on 2026-03-06 and last updated on 2026-06-30.

CVE-2026-26017

CVE-2026-26017 is a high-severity vulnerability in Coredns.io Coredns with a CVSS 3.x base score of 7.7. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-367.

Key facts

Severity: High (CVSS 3.x base score 7.7)
EPSS exploit prediction: 0% (30th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-10042
Weakness: CWE-367
Affected product: Coredns.io Coredns
Published: 2026-03-06
Last modified: 2026-06-30

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.

Frequently asked questions

What is CVE-2026-26017?: 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.
How severe is CVE-2026-26017?: CVE-2026-26017 has a CVSS 3.x base score of 7.7, rated high severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.
Is CVE-2026-26017 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (30th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-26017?: CVE-2026-26017 affects Coredns.io Coredns. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-26017?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
Does CVE-2026-26017 have an EU (EUVD) identifier?: Yes. CVE-2026-26017 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-10042.
When was CVE-2026-26017 published?: CVE-2026-26017 was published on 2026-03-06 and last updated on 2026-06-30.

References

Affected products (1)

cpe:2.3:a:coredns.io:coredns:*:*:*:*:*:*:*:*

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