Vulnerability in Coredns
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.
Vulnerability class: TOCTOU (Time-of-Check to Time-of-Use)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 7.7 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N.
EPSS exploit prediction
EPSS: 0.005 (40.1th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 40th percentile — 40.1% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.004 · newest: 0.005 · change: +0.001
Affected products
- Coredns — versions < 1.14.2
- Coredns.io Coredns
Weakness classification (CWE)
References
- github.com/coredns/coredns/security/advisories/GHSA-c9v3-4pv7-87pr (Mitigation, Vendor Advisory)
- github.com/coredns/coredns/releases/tag/v1.14.2 (Product, Release Notes)
- 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
- 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
- 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
- 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
- 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
- 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
Frequently asked questions
- What is CVE-2026-26017?
- CVE-2026-26017 is a high-severity vulnerability in Coredns, classified under Time-of-check Time-of-use (TOCTOU) Race Condition. CVSS score: 7.7/10. Published 2026-03-06.
- How severe is CVE-2026-26017?
- High severity. CVSS v3 base score is 7.7 out of 10.