diff --git a/core/attributedef.class.inc.php b/core/attributedef.class.inc.php
index 150a28cdc4..63830d8e41 100644
--- a/core/attributedef.class.inc.php
+++ b/core/attributedef.class.inc.php
@@ -4259,6 +4259,9 @@ public function GetMaxSize()
 
 	public static function RenderWikiHtml($sText, $bWikiOnly = false)
 	{
+		// N°8681 - Ensure to have a string value
+		$sText = $sText ?? '';
+
 		if (!$bWikiOnly) {
 			$sPattern = '/'.str_replace('/', '\/', utils::GetConfig()->Get('url_validation_pattern')).'/i';
 			if (preg_match_all(
diff --git a/core/inlineimage.class.inc.php b/core/inlineimage.class.inc.php
index 50242ff36b..fe4d4a7294 100644
--- a/core/inlineimage.class.inc.php
+++ b/core/inlineimage.class.inc.php
@@ -266,6 +266,9 @@ public static function OnFormCancel($sTempId): bool
 	 */
 	public static function FixUrls($sHtml)
 	{
+		// N°8681 - Ensure to have a string value
+		$sHtml = $sHtml ?? '';
+
 		$aNeedles = [];
 		$aReplacements = [];
 		// Find img tags with an attribute data-img-id
diff --git a/tests/php-unit-tests/unitary-tests/core/AttributeDefinitionTest.php b/tests/php-unit-tests/unitary-tests/core/AttributeDefinitionTest.php
index 739cf3b652..5c4e620a41 100644
--- a/tests/php-unit-tests/unitary-tests/core/AttributeDefinitionTest.php
+++ b/tests/php-unit-tests/unitary-tests/core/AttributeDefinitionTest.php
@@ -13,13 +13,6 @@ class AttributeDefinitionTest extends ItopDataTestCase
 {
 	public const CREATE_TEST_ORG = true;
 
-	protected function setUp(): void
-	{
-		parent::setUp();
-		require_once(APPROOT.'core/attributedef.class.inc.php');
-
-	}
-
 	public function testGetImportColumns()
 	{
 		$oAttributeDefinition = MetaModel::GetAttributeDef("ApplicationSolution", "status");
diff --git a/tests/php-unit-tests/unitary-tests/core/AttributeTextTest.php b/tests/php-unit-tests/unitary-tests/core/AttributeTextTest.php
new file mode 100644
index 0000000000..a84d5b897f
--- /dev/null
+++ b/tests/php-unit-tests/unitary-tests/core/AttributeTextTest.php
@@ -0,0 +1,78 @@
+<?php
+/*
+ * @copyright   Copyright (C) 2010-2026 Combodo SAS
+ * @license     http://opensource.org/licenses/AGPL-3.0
+ */
+
+namespace Combodo\iTop\Test\UnitTest\Core;
+
+use AttributeText;
+use Combodo\iTop\Test\UnitTest\ItopDataTestCase;
+
+class AttributeTextTest extends ItopDataTestCase
+{
+	protected \Organization $oTestOrganizationForAttributeText;
+
+	public function setUp(): void
+	{
+		parent::setUp();
+		$this->oTestOrganizationForAttributeText = $this->CreateOrganization('Test for AttributeTextTest');
+	}
+
+	/**
+     * @covers AttributeText::RenderWikiHtml
+     */
+    public function testRenderWikiHtml_nonWikiUrlVariants()
+    {
+        // String value
+        $sInput = 'This hyperlink https://combodo.com should be in an anchor tag.';
+        $sExpected = 'This hyperlink <a href="https://combodo.com">https://combodo.com</a> should be in an anchor tag.';
+        $this->assertEquals($sExpected, AttributeText::RenderWikiHtml($sInput));
+
+        // Empty string value
+        $this->assertEquals('', AttributeText::RenderWikiHtml(''));
+
+        // Null value
+        $this->assertEquals('', AttributeText::RenderWikiHtml(null));
+    }
+
+    /**
+     * @covers AttributeText::RenderWikiHtml
+     */
+    public function testRenderWikiHtml_bWikiOnlyAbsentOrFalse_shouldTransformBothRegularAndWikiHyperlinks()
+    {
+        $sInput = 'A regular hyperlink https://combodo.com and a wiki hyperlink to an existing object [[Organization:'.$this->oTestOrganizationForAttributeText->GetKey().']]';
+
+		// bWikiOnly default value
+        $sResult = AttributeText::RenderWikiHtml($sInput);
+        $this->assertStringContainsString('<a href="https://combodo.com">', $sResult);
+        $this->assertStringContainsString('class="object-ref-link"', $sResult);
+
+		// bWikiOnly = false
+        $sResult = AttributeText::RenderWikiHtml($sInput, false);
+        $this->assertStringContainsString('<a href="https://combodo.com">', $sResult);
+        $this->assertStringContainsString('class="object-ref-link"', $sResult);
+    }
+
+    /**
+     * @covers AttributeText::RenderWikiHtml
+     */
+    public function testRenderWikiHtml_bWikiOnlyToTrue_shouldNotTransformRegularHyperlinkButTransformWikiHyperlink()
+    {
+        $sInput = 'A regular hyperlink https://combodo.com and a wiki hyperlink to an existing object [[Organization:'.$this->oTestOrganizationForAttributeText->GetKey().']]';
+        $sResult = AttributeText::RenderWikiHtml($sInput, true);
+        $this->assertStringNotContainsString('<a href="https://combodo.com">', $sResult);
+        $this->assertStringContainsString('class="object-ref-link"', $sResult);
+    }
+
+    /**
+     * @covers AttributeText::RenderWikiHtml
+     */
+    public function testRenderWikiHtml_shouldTransformWikiHyperlinkForExistingObjectsOnly()
+    {
+        $sInput = 'A wiki hyperlink to a non existing object [[Organization:123456789]]  and a wiki hyperlink to an existing object [[Organization:'.$this->oTestOrganizationForAttributeText->GetKey().']]';
+        $sResult = AttributeText::RenderWikiHtml($sInput);
+        $this->assertStringContainsString('wiki_broken_link', $sResult);
+        $this->assertStringContainsString('class="object-ref-link"', $sResult);
+    }
+}
diff --git a/tests/php-unit-tests/unitary-tests/core/InlineImageTest.php b/tests/php-unit-tests/unitary-tests/core/InlineImageTest.php
index 68196a0439..1818c97e8c 100644
--- a/tests/php-unit-tests/unitary-tests/core/InlineImageTest.php
+++ b/tests/php-unit-tests/unitary-tests/core/InlineImageTest.php
@@ -59,4 +59,43 @@ public function OnFormCancelInvalidTempIdProvider()
 			],
 		];
 	}
+
+	/**
+	 * @covers InlineImage::FixUrls
+	 */
+	public function testFixUrls_shouldReturnAnEmptyStringIfNullOrEmptyStringPassed()
+	{
+		$sResult = InlineImage::FixUrls(null);
+		$this->assertEquals('', $sResult);
+
+		$sResult = InlineImage::FixUrls('');
+		$this->assertEquals('', $sResult);
+	}
+
+	/**
+	 * @covers InlineImage::FixUrls
+	 */
+	public function testFixUrls_shouldReturnUnchangedValueIfValueContainsNoImage()
+	{
+		$sHtml = '<div><p>Texte sans image</p></div>';
+		$sResult = InlineImage::FixUrls($sHtml);
+		$this->assertEquals($sHtml, $sResult);
+	}
+
+	/**
+	 * @covers InlineImage::FixUrls
+	 */
+	public function testFixUrls_shouldReplaceImagesSrcWithCurrentAppRootUrlAndSecret()
+	{
+		$sHtml = <<<HTML
+<div>
+	<img src="/images/test1.png" data-img-id="123" data-img-secret="abc" />
+	<img src="/images/test2.png" data-img-id="456" data-img-secret="def" />
+</div>
+HTML;
+		$sResult = InlineImage::FixUrls($sHtml);
+		$this->assertStringContainsString('<img', $sResult);
+		$this->assertStringContainsString(\utils::EscapeHtml(\utils::GetAbsoluteUrlAppRoot().INLINEIMAGE_DOWNLOAD_URL.'123&s=abc'), $sResult);
+		$this->assertStringContainsString(\utils::EscapeHtml(\utils::GetAbsoluteUrlAppRoot().INLINEIMAGE_DOWNLOAD_URL.'456&s=def'), $sResult);
+	}
 }