NULL pointer dereference in Coredns
CVE-2026-62299
CoreDNS is a DNS server written in Go. Prior to 1.14.5, the CoreDNS rewrite plugin supports edns0 rewrite rules with an optional revert flag, and two response rules, edns0SetResponseRule and edns0ReplaceResponseRule[T] in plugin/rewrite/edns0.go, call res.IsEdns0() and immediately dereference the returned *dns.OPT without a nil check when a downstream plugin returns a response with no OPT record. A remote, unauthenticated client can send a single ordinary DNS query matching a rewrite edns0 <local|nsid|subnet> <set|append|replace> ... revert rule, causing ResponseReverter in plugin/rewrite/reverter.go to panic, return SERVFAIL, and degrade availability, or crash the CoreDNS process if the debug directive disables recovery. This issue is fixed in version 1.14.5.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L.
EPSS exploit prediction
EPSS: 0.005 (44.2th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 44th percentile — 44.2% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.005 · newest: 0.005 · change: 0.000
Affected products
- Coredns — versions < 1.14.5
- Coredns.io Coredns
Weakness classification (CWE)
References
- github.com/coredns/coredns/commit/fc447d0658b093edc8cd29a6b171216a44a644c2 (Patch)
- github.com/coredns/coredns/pull/8190 (Patch, Issue Tracking)
- github.com/coredns/coredns/releases/tag/v1.14.5 (Release Notes)
- github.com/coredns/coredns/security/advisories/GHSA-9pmm-cxww-rrr7 (Exploit, Third Party Advisory)
Frequently asked questions
- What is CVE-2026-62299?
- CVE-2026-62299 is a medium-severity vulnerability in Coredns, classified under NULL Pointer Dereference. CVSS score: 5.3/10. Published 2026-07-16.
- How severe is CVE-2026-62299?
- Medium severity. CVSS v3 base score is 5.3 out of 10.