Vulnerability in nginx (CVE-2026-42946)
Summary
Vulnerability in nginx (CVE-2026-42946). Confidential information can be exposed externally. Mitigation: upgrade to 1.30.1 or later.
Original description
The description as published by the source.
A vulnerability exists in the ngx_http_scgi_module and ngx_http_uwsgi_module modules that may result in excessive memory allocation or an over-read of data. When scgi_pass or uwsgi_pass is configured, an unauthenticated attacker with man-in-the-middle (MITM) ability to control responses from an upstream server may be able to read the memory of the NGINX worker process or restart it. Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.
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-2026-42946 has been found in nginx.
Confidential information can be exposed externally. CVSS score: 6.5/10.
What to do: upgrade nginx to 1.30.1 or later.
If unsure, ask your IT team or search "nginx CVE-2026-42946" on the vendor's site.
CVE-2026-42946 (nginx) — CWE-789 / CVSS v3 6.5
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
Patched: 1.30.1 — 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-789) exists in nginx.
Check the vendor advisory for the affected versions of nginx.
Severity: Medium (CVSS 6.5/10). Confidential information can be exposed externally.
Update to 1.30.1.
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 'nginx' . 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 'nginx' . | 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
nginx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 nginx to 1.30.1ステージング環境で 1.30.1 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
- Alpine Linux ALPINE-CVE-2026-42946 nginx Fixed in: 1.28.3-r1
- BellSoft Alpaquita BELL-CVE-2026-42946 nginx Fixed in: 1.22.1-r5
- Debian DEBIAN-CVE-2026-42946 nginx Fixed in: 1.18.0-6.1+deb11u6
- Ubuntu UBUNTU-CVE-2026-42946 nginx Fixed in: 1.4.6-1ubuntu3.9+esm6
References
- patch f5sirt@f5.com
- web nvd.nist.gov
- web github.com