Cross-Site Scripting (XSS) in Dify (CVE-2026-42138)
Summary
Cross-site scripting in Dify (CVE-2026-42138). Risk of unauthorized operations or information disclosure. Exploitable via POST /api/files/upload.
Original description
The description as published by the source.
Dify is an open-source LLM app development platform. Prior to version 1.13.1, using the method POST /api/files/upload, any unauthenticated user can upload an SVG file with XSS. The method POST /v1/files/upload, which requires authentication through the application API, is also vulnerable. This issue has been patched in version 1.13.1.
Source: NIST National Vulnerability Database NVD
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-2026-42138 has been found in Dify.
Attackers can target a specific entry point like POST /api/files/upload over the network to misuse the product.
Risk of unauthorized operations or information disclosure. CVSS score: 6.1/10.
What to do: apply the vendor's official patched release.
If unsure, ask your IT team or search "Dify CVE-2026-42138" on the vendor's site.
CVE-2026-42138 (Dify) — CWE-79 / CVSS v3 6.1
Attack vector: remote (network-reachable) / unauthenticated
Attack surface: POST /api/files/upload / POST /v1/files/upload
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 Dify. Attackers reach the vulnerable code path via POST /api/files/upload without authentication.
Check the vendor advisory for the affected versions of Dify. Attack surface: POST /api/files/upload / POST /v1/files/upload.
Severity: Medium (CVSS 6.1/10). 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/files/upload requests with malformed payloads or SQL meta-characters. Run grep -r 'Dify' . 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 'Dify' . | 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
Difyを grep し、稼働しているサービス・バージョンを把握する。 -
2Hunt for indicators of compromise detect
grep 'POST /api/files/upload' /var/log/nginx/access.log | grep -E '(unusual_payload|sqli_pattern)'アクセスログで
POST /api/files/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。 -
3Post-deployment verification verify
Replay attack against POST /api/files/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 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
- exploit github.com
- web security-advisories@github.com