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Vulnerability · Published Jul 16, 2026 · Assigned by GitHub_M

CVE-2026-62299CoreDNS: rewrite-plugin EDNS0 response-revert nil-pointer panic (remote DoS) when a downstream plugin returns a response with no OPT record

Medium 5.3

In plain English

A medium-severity null pointer dereference in coredns from coredns. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.5% (higher than 46% of all known vulnerabilities).

Severity (CVSS 3.1)5.3Medium
Exploit odds (30 days)0.5%top 54.5% of all CVEs
Exploited in the wildNo reportsCISA SSVC: poc
Attack toolingNoneno public tooling known

Official description

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.

Affected products (as reported)

VendorProductVersions
coredns coredns < 1.14.5

Weakness: CWE-476 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

References