diff --git a/README.md b/README.md
index 32d77a87..39f11522 100644
--- a/README.md
+++ b/README.md
@@ -479,6 +479,7 @@ export const recommendedTest_6_2_40: DocumentTest
 export const recommendedTest_6_2_41: DocumentTest
 export const recommendedTest_6_2_43: DocumentTest
 export const recommendedTest_6_2_47: DocumentTest
+export const recommendedTest_6_2_48: DocumentTest
 ```
 
 [(back to top)](#bsi-csaf-validator-lib)
diff --git a/csaf_2_1/recommendedTests.js b/csaf_2_1/recommendedTests.js
index 594f22a4..c7da1b4f 100644
--- a/csaf_2_1/recommendedTests.js
+++ b/csaf_2_1/recommendedTests.js
@@ -40,3 +40,4 @@ export { recommendedTest_6_2_40 } from './recommendedTests/recommendedTest_6_2_4
 export { recommendedTest_6_2_41 } from './recommendedTests/recommendedTest_6_2_41.js'
 export { recommendedTest_6_2_43 } from './recommendedTests/recommendedTest_6_2_43.js'
 export { recommendedTest_6_2_47 } from './recommendedTests/recommendedTest_6_2_47.js'
+export { recommendedTest_6_2_48 } from './recommendedTests/recommendedTest_6_2_48.js'
diff --git a/csaf_2_1/recommendedTests/recommendedTest_6_2_48.js b/csaf_2_1/recommendedTests/recommendedTest_6_2_48.js
new file mode 100644
index 00000000..7986c7aa
--- /dev/null
+++ b/csaf_2_1/recommendedTests/recommendedTest_6_2_48.js
@@ -0,0 +1,108 @@
+import Ajv from 'ajv/dist/jtd.js'
+
+const ajv = new Ajv()
+
+const branchSchema = /** @type {const} */ ({
+  additionalProperties: true,
+  optionalProperties: {
+    category: { type: 'string' },
+    name: { type: 'string' },
+    branches: {
+      elements: {
+        additionalProperties: true,
+        properties: {},
+      },
+    },
+  },
+})
+
+/*
+  This is the jtd schema that needs to match the input document so that the
+  test is activated. If this schema doesn't match it normally means that the input
+  document does not validate against the csaf json schema or optional fields that
+  the test checks are not present.
+ */
+const inputSchema = /** @type {const} */ ({
+  additionalProperties: true,
+  properties: {
+    product_tree: {
+      additionalProperties: true,
+      optionalProperties: {
+        branches: {
+          elements: branchSchema,
+        },
+      },
+    },
+  },
+})
+
+const validateInput = ajv.compile(inputSchema)
+const validateBranch = ajv.compile(branchSchema)
+
+/**
+ * @typedef {import('ajv/dist/core').JTDDataType<typeof branchSchema>} Branch
+ */
+
+/**
+ * This implements the recommended test 6.2.48 of the CSAF 2.1 standard.
+ *
+ * @param {any} doc
+ */
+export function recommendedTest_6_2_48(doc) {
+  const ctx = {
+    warnings:
+      /** @type {Array<{ instancePath: string; message: string }>} */ ([]),
+  }
+
+  if (!validateInput(doc)) {
+    return ctx
+  }
+
+  const branches = doc.product_tree?.branches ?? []
+  branches.forEach((branch, index) => {
+    checkBranch(branch, `/product_tree/branches/${index}`, ctx.warnings)
+  })
+
+  return ctx
+}
+
+/**
+ * Recursively checks a branch and its nested branches.
+ *
+ * @param {Branch} branch
+ * @param {string} basePath
+ * @param {Array<{ instancePath: string; message: string }>} warnings
+ */
+function checkBranch(branch, basePath, warnings) {
+  if (!validateBranch(branch)) return
+  if (branch.category === 'vendor') {
+    if (
+      branch.name !== undefined &&
+      normalizeBranchName(branch.name) === 'opensource'
+    ) {
+      warnings.push({
+        instancePath: `${basePath}/name`,
+        message:
+          'Branch with category "vendor" should not have the name "Open Source"',
+      })
+    }
+  }
+
+  if (Array.isArray(branch.branches)) {
+    branch.branches.forEach(
+      (/** @type {Branch} */ childBranch, /** @type {number} */ index) => {
+        checkBranch(childBranch, `${basePath}/branches/${index}`, warnings)
+      }
+    )
+  }
+}
+
+/**
+ * Normalizes a string to be case and white space insensitive.
+ *
+ * @param {string} str
+ * @returns {string}
+ */
+function normalizeBranchName(str) {
+  return str.replaceAll(/\s+/g, '').toLowerCase()
+}
diff --git a/tests/csaf_2_1/oasis.js b/tests/csaf_2_1/oasis.js
index 8f223924..6dcd63ed 100644
--- a/tests/csaf_2_1/oasis.js
+++ b/tests/csaf_2_1/oasis.js
@@ -50,7 +50,6 @@ const excluded = [
   '6.2.44',
   '6.2.45',
   '6.2.46',
-  '6.2.48',
   '6.2.49',
   '6.2.50.1',
   '6.2.50.2',
diff --git a/tests/csaf_2_1/recommendedTest_6_2_48.js b/tests/csaf_2_1/recommendedTest_6_2_48.js
new file mode 100644
index 00000000..ed166ad8
--- /dev/null
+++ b/tests/csaf_2_1/recommendedTest_6_2_48.js
@@ -0,0 +1,30 @@
+import assert from 'node:assert/strict'
+import { recommendedTest_6_2_48 } from '../../csaf_2_1/recommendedTests/recommendedTest_6_2_48.js'
+
+describe('recommendedTest_6_2_48', function () {
+  it('only runs on relevant documents', function () {
+    assert.equal(recommendedTest_6_2_48({}).warnings.length, 0)
+  })
+
+  it('does not warn when product_tree has no branches', function () {
+    assert.equal(
+      recommendedTest_6_2_48({ product_tree: {} }).warnings.length,
+      0
+    )
+  })
+
+  it('skips invalid child branches that do not pass schema validation', function () {
+    const result = recommendedTest_6_2_48({
+      product_tree: {
+        branches: [
+          {
+            category: 'vendor',
+            name: 'Open Source Company',
+            branches: [42, null],
+          },
+        ],
+      },
+    })
+    assert.equal(result.warnings.length, 0)
+  })
+})