diff --git a/advisories/github-reviewed/2024/12/GHSA-r87q-fj25-f8jf/GHSA-r87q-fj25-f8jf.json b/advisories/github-reviewed/2024/12/GHSA-r87q-fj25-f8jf/GHSA-r87q-fj25-f8jf.json
new file mode 100644
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+++ b/advisories/github-reviewed/2024/12/GHSA-r87q-fj25-f8jf/GHSA-r87q-fj25-f8jf.json
@@ -0,0 +1,57 @@
+{
+  "schema_version": "1.4.0",
+  "id": "GHSA-r87q-fj25-f8jf",
+  "modified": "2024-12-23T18:18:54Z",
+  "published": "2024-12-23T18:18:54Z",
+  "aliases": [
+    "CVE-2024-56364"
+  ],
+  "summary": "Cross-site Scripting vulnerability in SimpleXLSXEx::readThemeColors, SimpleXLSXEx::getColorValue and SimpleXLSX::toHTMLEx",
+  "details": "### Impact\nWhen calling the extended toHTMLEx method, it is possible to execute arbitrary JavaScript code.\n\n### Patches\nThe supplied patch resolves this vulnerability for SimpleXLSX. Use 1.1.13\n\n### Workarounds\nDon't use data publication via toHTMLEx\n\n***\nThis vulnerability was discovered by Aleksey Solovev (Positive Technologies)\n",
+  "severity": [
+    {
+      "type": "CVSS_V3",
+      "score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:N/A:N"
+    }
+  ],
+  "affected": [
+    {
+      "package": {
+        "ecosystem": "Packagist",
+        "name": "shuchkin/simplexlsx"
+      },
+      "ranges": [
+        {
+          "type": "ECOSYSTEM",
+          "events": [
+            {
+              "introduced": "1.0.12"
+            },
+            {
+              "fixed": "1.1.13"
+            }
+          ]
+        }
+      ]
+    }
+  ],
+  "references": [
+    {
+      "type": "WEB",
+      "url": "https://github.com/shuchkin/simplexlsx/security/advisories/GHSA-r87q-fj25-f8jf"
+    },
+    {
+      "type": "PACKAGE",
+      "url": "https://github.com/shuchkin/simplexlsx"
+    }
+  ],
+  "database_specific": {
+    "cwe_ids": [
+      "CWE-79"
+    ],
+    "severity": "MODERATE",
+    "github_reviewed": true,
+    "github_reviewed_at": "2024-12-23T18:18:54Z",
+    "nvd_published_at": null
+  }
+}
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