From 70a1c8428480f6c3f71779f67309c3a9bf790463 Mon Sep 17 00:00:00 2001
From: crowdsec-automation
 <63358111+crowdsec-automation@users.noreply.github.com>
Date: Wed, 9 Sep 2026 15:14:05 +0200
Subject: [PATCH 1/4] Add vpatch-CVE-2026-18577 rule

---
 .../crowdsecurity/vpatch-CVE-2026-18577.yaml  | 24 +++++++++++++++++++
 1 file changed, 24 insertions(+)
 create mode 100644 appsec-rules/crowdsecurity/vpatch-CVE-2026-18577.yaml

diff --git a/appsec-rules/crowdsecurity/vpatch-CVE-2026-18577.yaml b/appsec-rules/crowdsecurity/vpatch-CVE-2026-18577.yaml
new file mode 100644
index 00000000000..93287e1cf28
--- /dev/null
+++ b/appsec-rules/crowdsecurity/vpatch-CVE-2026-18577.yaml
@@ -0,0 +1,24 @@
+## autogenerated on 2026-09-09 13:14:02
+name: crowdsecurity/vpatch-CVE-2026-18577
+description: 'Detects requests targeting the N-able N-central authentication endpoint associated with the authentication bypass.'
+rules:
+  - zones:
+      - URI
+    transform:
+      - lowercase
+      - urldecode
+    match:
+      type: equals
+      value: '/login'
+
+labels:
+  type: exploit
+  service: http
+  confidence: 3
+  spoofable: 0
+  behavior: 'http:exploit'
+  label: 'N-Central - Authentication Bypass'
+  classification:
+    - cve.CVE-2026-18577
+    - attack.T1190
+    - cwe.CWE-288

From 2892ddef71929adf0ec2601c269a53b83188e5c4 Mon Sep 17 00:00:00 2001
From: crowdsec-automation
 <63358111+crowdsec-automation@users.noreply.github.com>
Date: Wed, 9 Sep 2026 15:14:07 +0200
Subject: [PATCH 2/4] Add vpatch-CVE-2026-18577 test config

---
 .appsec-tests/vpatch-CVE-2026-18577/config.yaml | 5 +++++
 1 file changed, 5 insertions(+)
 create mode 100644 .appsec-tests/vpatch-CVE-2026-18577/config.yaml

diff --git a/.appsec-tests/vpatch-CVE-2026-18577/config.yaml b/.appsec-tests/vpatch-CVE-2026-18577/config.yaml
new file mode 100644
index 00000000000..4ec97271748
--- /dev/null
+++ b/.appsec-tests/vpatch-CVE-2026-18577/config.yaml
@@ -0,0 +1,5 @@
+## autogenerated on 2026-09-09 13:14:02
+appsec-rules:
+  - ./appsec-rules/crowdsecurity/base-config.yaml
+  - ./appsec-rules/crowdsecurity/vpatch-CVE-2026-18577.yaml
+nuclei_template: CVE-2026-18577.yaml

From c826fe1510059922d226325cc60c18a1bdfc9590 Mon Sep 17 00:00:00 2001
From: crowdsec-automation
 <63358111+crowdsec-automation@users.noreply.github.com>
Date: Wed, 9 Sep 2026 15:14:09 +0200
Subject: [PATCH 3/4] Add CVE-2026-18577.yaml test

---
 .../vpatch-CVE-2026-18577/CVE-2026-18577.yaml   | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)
 create mode 100644 .appsec-tests/vpatch-CVE-2026-18577/CVE-2026-18577.yaml

diff --git a/.appsec-tests/vpatch-CVE-2026-18577/CVE-2026-18577.yaml b/.appsec-tests/vpatch-CVE-2026-18577/CVE-2026-18577.yaml
new file mode 100644
index 00000000000..843511470c4
--- /dev/null
+++ b/.appsec-tests/vpatch-CVE-2026-18577/CVE-2026-18577.yaml
@@ -0,0 +1,17 @@
+## autogenerated on 2026-09-09 13:14:02
+id: CVE-2026-18577
+info:
+  name: CVE-2026-18577
+  author: crowdsec
+  severity: info
+  description: CVE-2026-18577 testing
+  tags: appsec-testing
+http:
+  - method: GET
+    path:
+      - '{{BaseURL}}/login'
+    cookie-reuse: true
+    matchers:
+      - type: status
+        status:
+          - 403

From 122d571d7d95a23a2bc8b7294319d8a7d60e1190 Mon Sep 17 00:00:00 2001
From: crowdsec-automation
 <63358111+crowdsec-automation@users.noreply.github.com>
Date: Wed, 9 Sep 2026 15:14:11 +0200
Subject: [PATCH 4/4] Add vpatch-CVE-2026-18577 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 94d0ed3d1ea..3d46f95f81f 100644
--- a/collections/crowdsecurity/appsec-virtual-patching.yaml
+++ b/collections/crowdsecurity/appsec-virtual-patching.yaml
@@ -71,6 +71,7 @@ appsec-rules:
 - crowdsecurity/vpatch-CVE-2018-13379
 - crowdsecurity/vpatch-CVE-2022-26134
 - crowdsecurity/vpatch-CVE-2026-1557
+- crowdsecurity/vpatch-CVE-2026-18577
 - crowdsecurity/vpatch-CVE-2024-34102
 - crowdsecurity/vpatch-CVE-2024-29973
 - crowdsecurity/vpatch-CVE-2022-41082