Machine-written summary
Summary written by Claude Haiku from the source advisory. Not reviewed by a person.
CoreDNS versions before 1.14.7 accept RFC 2136 UPDATE messages over DoH, DoH3, DoQ, and DNS-over-gRPC and forward them unchanged through the proxy or forward plugin, while UDP, TCP, and DoT reject them. An unauthenticated client who can reach one of those listeners can, when the upstream trusts CoreDNS's source address or connection instead of requiring TSIG, add, replace, or delete records. Upgrade to CoreDNS 1.14.7 or later; the source does not list a workaround other than requiring end-to-end TSIG on the upstream.
Not analysed yet
We haven’t published our analysis of this Advisory yet. Once a person has reviewed it, this page will say what’s vulnerable, what has to be true for your app to be affected, and how to check.
Severity and exploitation
| Score | Rating | CVSS | Vector | Source |
|---|---|---|---|---|
| 7.5 | High | 3.1 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N | CNA (GitHub_M) |
- CISA KEV Not listed.
- EPSS 0.0044, the 38th percentile, on 5 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.
Timeline
- 31 Oct 2026, 14:12 UTC First seen by agentprime
- 31 Oct 2026, 14:12 UTC Confirmed by OSV
Sources
- GitHub Advisory Database: GHSA-9gm5-9rfh-m6vx
- OSV: GHSA-9gm5-9rfh-m6vx
- github.com/coredns/coredns/security/advisories/GHSA-9gm5-9rfh-m6vx
- nvd.nist.gov/vuln/detail/CVE-2026-86003
- github.com/coredns/coredns/commit/530b0a5ff2ad68cc0421f10dd93568945cc671c9
- github.com/coredns/coredns
- github.com/coredns/coredns/releases/tag/v1.14.7