Vulnerability in nats (CVE-2026-33216)
Summary
Vulnerability in nats (CVE-2026-33216). Confidential information can be exposed externally. Mitigation: upgrade to 2.11.15, 2.12.6 or later.
Original description
The description as published by the source.
NATS-Server is a High-Performance server for NATS.io, a cloud and edge native messaging system. Prior to versions 2.11.15 and 2.12.6, for MQTT deployments using usercodes/passwords: MQTT passwords are incorrectly classified as a non-authenticating identity statement (JWT) and exposed via monitoring endpoints. Versions 2.11.14 and 2.12.6 contain a fix. As a workaround, ensure monitoring end-points are adequately secured. Best practice remains to not expose the monitoring endpoint to the Internet or other untrusted network users.
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-2026-33216 has been found in nats.
Confidential information can be exposed externally. CVSS score: 8.6/10.
What to do: upgrade nats to 2.11.15, 2.12.6 or later.
If unsure, ask your IT team or search "nats CVE-2026-33216" on the vendor's site.
CVE-2026-33216 (nats) — CWE-256 / CVSS v3 8.6
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
Patched: 2.11.15, 2.12.6 — 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-256) exists in nats.
Check the vendor advisory for the affected versions of nats.
Severity: High (CVSS 8.6/10). Confidential information can be exposed externally.
Update to 2.11.15, 2.12.6.
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 'nats' . 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
-
1Identify exposure identify
grep -r 'nats' . | 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
nats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 nats to 2.11.15, 2.12.6ステージング環境で 2.11.15, 2.12.6 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。
-
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
Fix status by distribution
Fixed packages published by each distribution for this CVE
- Debian DEBIAN-CVE-2026-33216 nats-server
- Ubuntu UBUNTU-CVE-2026-33216 nats-server
References
- advisory advisories.nats.io
- advisory github.com
- patch github.com
- web access.redhat.com
- web access.redhat.com
- web access.redhat.com
- web access.redhat.com
- web bugzilla.redhat.com
- web security.access.redhat.com
- web nvd.nist.gov