Authorization Flaw in getgrav/grav-plugin-api (CVE-2026-42843)
Summary
Vulnerability in getgrav/grav-plugin-api (CVE-2026-42843). Successful exploitation can lead to full system takeover. Exploitable via api.access. Mitigation: upgrade to 1.0.0-beta.15 or later.
Original description
The description as published by the source.
Summary
An insecure direct object reference and logic flaw in the Grav API plugin (UsersController::update) allows any authenticated user with basic API access (api.access) to modify their own permission configuration. An attacker can exploit this to escalate their privileges to Super Administrator (admin.super and api.super), leading to full system compromise and potential RCE.
Details
The vulnerability is located in user/plugins/api/classes/Api/Controllers/UsersController.php within the update method.
The API allows users to update their own profiles if they possess the basic api.access permission:
// UsersController.php -> update()
$isSelf = $currentUser->username === $username;
if (!$isSelf) {
$this->requirePermission($request, 'api.users.write');
} else {
// Self-edit only requires api.access
$this->requirePermission($request, 'api.access');
}
However, when filtering the fields that are allowed to be updated via a PATCH request, the access field (which defines the user's role and permissions) is indiscriminately included in the $allowedFields whitelist for all users:
// Partial update - only update provided fields
$allowedFields = ['email', 'fullname', 'title', 'state', 'language', 'content_editor', 'access', 'twofa_enabled'];
foreach ($allowedFields as $field) {
if (array_key_exists($field, $body)) {
$user->set($field, $body[$field]);
}
}
Because there is no secondary check to verify i…
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-2026-42843 has been found in getgrav/grav-plugin-api.
Attackers can target a specific entry point like api.access over the network to misuse the product.
Successful exploitation can lead to full system takeover. CVSS score: 8.8/10.
What to do: upgrade getgrav/grav-plugin-api to 1.0.0-beta.15 or later.
If unsure, ask your IT team or search "getgrav/grav-plugin-api CVE-2026-42843" on the vendor's site.
CVE-2026-42843 (getgrav/grav-plugin-api) — CWE-863 / CVSS v3 8.8
Attack vector: remote (network-reachable) / no user interaction
Attack surface: api.access / admin.super / api.super / update
Patched: 1.0.0-beta.15 — 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.
Incorrect authorization (CWE-863) exists in getgrav/grav-plugin-api. Attackers reach the vulnerable code path via api.access.
Check the vendor advisory for the affected versions of getgrav/grav-plugin-api. Attack surface: api.access / admin.super / api.super / update.
Severity: High (CVSS 8.8/10). Successful exploitation can lead to full system takeover.
Update to 1.0.0-beta.15.
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 'getgrav/grav-plugin-api' . 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 'getgrav/grav-plugin-api' . | 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-api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 getgrav/grav-plugin-api to 1.0.0-beta.15ステージング環境で 1.0.0-beta.15 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
References
- advisory nvd.nist.gov
- exploit github.com
- package github.com
- web github.com
- web github.com