Cross-Site Scripting (XSS) in Grav API plugin (CVE-2026-61456)
Summary
Cross-site scripting in Grav API plugin (CVE-2026-61456). Risk of unauthorized operations or information disclosure. Exploitable via POST /api/v1/media.
Original description
The description as published by the source.
The Grav API plugin (getgrav/grav-plugin-api) before 1.0.3 fails to sanitize SVG files uploaded through the POST /api/v1/media endpoint. The HandlesMediaUploads::processUploadedFile() method validates only the file extension and never invokes Security::sanitizeSVG(), so an authenticated attacker with the api.media.write permission can upload an SVG containing arbitrary JavaScript. The file is stored unmodified and served with Content-Type: image/svg+xml; when an administrator opens it in a browser (directly or via /), the embedded script executes in their session context, enabling cookie theft and session hijacking.
Source: GitHub Security Advisories (Global) 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-2026-61456 has been found in Grav API plugin.
Attackers can target a specific entry point like POST /api/v1/media over the network to misuse the product.
Risk of unauthorized operations or information disclosure. CVSS score: 4.6/10.
What to do: apply the vendor's official patched release.
If unsure, ask your IT team or search "Grav API plugin CVE-2026-61456" on the vendor's site.
CVE-2026-61456 (Grav API plugin) — CWE-79 / CVSS v3 4.6
Attack vector: remote (network-reachable)
Attack surface: POST /api/v1/media
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.
Cross-site scripting (XSS) (CWE-79) exists in Grav API plugin. Attackers reach the vulnerable code path via POST /api/v1/media.
Check the vendor advisory for the affected versions of Grav API plugin. Attack surface: POST /api/v1/media.
Severity: Medium (CVSS 4.6/10). Risk of unauthorized operations or information disclosure.
Update to the patched release per vendor advisory.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual POST /api/v1/media requests with malformed payloads or SQL meta-characters. Audit SBOM/dependencies to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
-
1Identify exposure identify
Audit SBOM/dependencies for affected components.資産台帳・SBOM・依存マニフェストで Grav API plugin を使っているサービスとバージョンを洗い出す。
-
2Hunt for indicators of compromise detect
grep 'POST /api/v1/media' /var/log/nginx/access.log | grep -E '(unusual_payload|sqli_pattern)'アクセスログで
POST /api/v1/media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。 -
3Post-deployment verification verify
Replay attack against POST /api/v1/media 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 2 と同じログクエリでアラート再発が無いか継続監視。
References
- advisory github.com
- advisory nvd.nist.gov
- advisory vulncheck.com
- advisory github.com
- web github.com