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CVE-2026-42845
Vulnerability in getgrav/grav-plugin-form (CVE-2026-42845)
Summary
vulnerability in getgrav/grav-plugin-form (CVE-2026-42845). Risk of unauthorized operations or information disclosure. Exploitable via `GET /upload`. Mitigation: upgrade to `9.1.0` or later.
AI summary snake-internal / snake-material-v2
A vulnerability tracked as **CVE-2026-42845** has been found in getgrav/grav-plugin-form.
Attackers can target a specific entry point like `GET /upload` over the network to misuse the product.
Risk of unauthorized operations or information disclosure. CVSS score: ?/10.
What to do: upgrade getgrav/grav-plugin-form to **9.1.0** or later.
If unsure, ask your IT team or search "getgrav/grav-plugin-form CVE-2026-42845" on the vendor's site.
CVE-2026-42845 (getgrav/grav-plugin-form) — CWE-20 /
Attack surface: GET /upload / POST /upload / `filename` / `default.md`
Patched: `9.1.0` — 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.
❓ What is the problem
**A vulnerability** (CWE-20) exists in getgrav/grav-plugin-form. Attackers reach the vulnerable code path via `GET /upload` without authentication.
📍 Affected scope
getgrav/grav-plugin-form — . Attack surface: GET /upload / POST /upload / `filename` / `default.md`.
🔥 Severity
Severity: ?. Risk of unauthorized operations or information disclosure
🔧 How to fix
Update to **9.1.0**.
🛡️ Workaround
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
🔍 Detection
Search webserver/proxy logs for unusual `GET /upload` requests with malformed payloads or SQL meta-characters. Run `grep -r 'getgrav/grav-plugin-form' .` against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.
Response Actions (7 steps)
Concrete steps and command examples for SOC/SRE teams to execute in order
-
1Identify exposure identify
grep -r 'getgrav/grav-plugin-form' . | 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 `getgrav/grav-plugin-form` を grep し、稼働しているサービス・バージョンを把握する。
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3Hunt for indicators of compromise detect
grep 'GET /upload' /var/log/nginx/access.log | grep -E '(unusual_payload|sqli_pattern)'アクセスログで `GET /upload` への異常なリクエスト (不正な認証ヘッダ・SQLメタ文字)を過去 30〜90日分捜索。WAF/SIEM があれば該当パスのアラート発火履歴を確認。
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6Apply patch patch
Upgrade getgrav/grav-plugin-form to 9.1.0ステージング環境で 9.1.0 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と、Step 3 で見つけた異常検知の続報チェックを含めること。
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7Post-deployment verification verify
Replay attack against GET /upload on staging to confirm patch closes the vector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 Step 3 と同じログクエリでアラート再発が無いか継続監視。
Affected packages
composer
getgrav/grav-plugin-form
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"9.1.0"}]}]
Packagist
getgrav/grav-plugin-form
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"9.1.0"}]}]
References
- advisory https://nvd.nist.gov/vuln/detail/CVE-2026-42845
- package https://github.com/getgrav/grav
- web https://github.com/getgrav/grav-plugin-form/commit/48bacc4187e1cff815000e526d5ca2878484867f
- web https://github.com/getgrav/grav/security/advisories/GHSA-w4rc-p66m-x6qq
- web https://github.com/advisories/GHSA-w4rc-p66m-x6qq