Vulnerability in flowise (CVE-2026-42861)
Summary
Vulnerability in flowise (CVE-2026-42861). Confidential information can be exposed externally. Exploitable via PUT /api/v1/variables/{variableId}. Mitigation: upgrade to 3.1.2 or later.
Original description
The description as published by the source.
Summary
A Mass Assignment vulnerability exists in the variable update endpoint of FlowiseAI.
The endpoint allows authenticated users to modify server-controlled properties such as workspaceId, createdDate, and updatedDate when updating a variable resource.
Due to missing server-side validation and authorization checks, an attacker can manipulate the workspaceId field and reassign variables to arbitrary workspaces.
This behavior may break tenant isolation in multi-workspace environments.
Details
The endpoint responsible for updating variables:
PUT /api/v1/variables/{variableId}
accepts a JSON request body containing the variable definition.
However, the backend does not restrict which attributes can be modified by the client. As a result, user-controlled request bodies can include internal properties that should normally be controlled exclusively by the server.
Server-controlled fields that can be manipulated include:
- workspaceId
- createdDate
- updatedDate
These fields appear to be directly mapped to the database entity without strict input validation or authorization checks.
For example, the following request body was accepted by the server:
{
"name": "aaa",
"value": "bbbe",
"type": "static",
"createdDate": "2016-03-06T17:59:30.000Z",
"updatedDate": "2016-03-06T18:00:17.000Z",
"workspaceId": "11111111-2222-3333-4444-555555555555"
}
The server accepted the attacker-controlled workspaceId and metadata fields and persisted them…
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-2026-42861 has been found in flowise.
Attackers can target a specific entry point like PUT /api/v1/variables/{variableId} over the network to misuse the product.
Confidential information can be exposed externally. CVSS score: 9.6/10.
What to do: upgrade flowise to 3.1.2 or later.
If unsure, ask your IT team or search "flowise CVE-2026-42861" on the vendor's site.
CVE-2026-42861 (flowise) — CWE-284 / CVSS v3 9.6
Attack vector: remote (network-reachable) / no user interaction
Attack surface: PUT /api/v1/variables/{variableId} / PUT /api/v1/variables/
Patched: 3.1.2 — 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-284) exists in flowise. Attackers reach the vulnerable code path via PUT /api/v1/variables/{variableId}.
Check the vendor advisory for the affected versions of flowise. Attack surface: PUT /api/v1/variables/{variableId} / PUT /api/v1/variables/.
Severity: Critical (CVSS 9.6/10). Confidential information can be exposed externally.
Update to 3.1.2.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual PUT /api/v1/variables/{variableId} requests with malformed payloads or SQL meta-characters. Run grep -r 'flowise' . 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 'flowise' . | 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
flowise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 'PUT /api/v1/variables/{variableId}' /var/log/nginx/access.log | grep -E '(unusual_payload|sqli_pattern)'アクセスログで
PUT /api/v1/variables/{variableId}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。 -
3Apply patch patch
Upgrade flowise to 3.1.2ステージング環境で 3.1.2 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 2 で見つけた異常検知の続報チェックを含めること。
-
4Post-deployment verification verify
Replay attack against PUT /api/v1/variables/{variableId} 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。
Affected packages
References
- advisory nvd.nist.gov
- exploit security-advisories@github.com
- package github.com
- web security-advisories@github.com
- web github.com