Vulnerability in github.com/coredns/coredns (CVE-2026-33489)
Summary
Vulnerability in github.com/coredns/coredns (CVE-2026-33489). Confidential information can be exposed externally. Mitigation: upgrade to 1.14.3 or later.
Original description
The description as published by the source.
CoreDNS is a DNS server that chains plugins. In versions prior to 1.14.3, the transfer plugin can select the wrong ACL stanza when both a parent zone and a more-specific subzone are configured. The longestMatch() function in plugin/transfer/transfer.go uses a lexicographic string comparison instead of an actual longest-suffix match to select the winning zone. As a result, a permissive parent-zone transfer rule can override a restrictive subzone rule depending on zone name ordering (e.g., "example.org." > "a.example.org." lexicographically). This allows an unauthorized remote client to perform AXFR/IXFR for the subzone and retrieve its full zone contents. This issue has been fixed in version 1.14.3.
Source: NIST National Vulnerability Database NVD GitHub Advisory
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2026-33489 has been found in github.com/coredns/coredns.
Confidential information can be exposed externally. CVSS score: 7.5/10.
What to do: upgrade github.com/coredns/coredns to 1.14.3 or later.
If unsure, ask your IT team or search "github.com/coredns/coredns CVE-2026-33489" on the vendor's site.
CVE-2026-33489 (github.com/coredns/coredns) — CWE-862 / CVSS v3 7.5
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
Patched: 1.14.3 — apply immediately
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
A vulnerability (CWE-862) exists in github.com/coredns/coredns.
Check the vendor advisory for the affected versions of github.com/coredns/coredns.
Severity: High (CVSS 7.5/10). Confidential information can be exposed externally.
Update to 1.14.3.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r 'github.com/coredns/coredns' . against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
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1Identify exposure identify
grep -r 'github.com/coredns/coredns' . | grep -v node_modulesリポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で
github.com/coredns/corednsを grep し、稼働しているサービス・バージョンを把握する。 -
2Apply patch patch
Upgrade github.com/coredns/coredns to 1.14.3ステージング環境で 1.14.3 に上げて回帰テスト → 本番反映。回帰テストはアプリの主要ハッピーパスを含めること。
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3Post-deployment verification verify
Confirm patched version is live in productionパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。
Affected packages
References
- advisory github.com
- advisory nvd.nist.gov
- advisory github.com
- package github.com
- web github.com
- web github.com