diff --git a/poi-ooxml/src/main/java/org/apache/poi/xdgf/usermodel/XDGFSheet.java b/poi-ooxml/src/main/java/org/apache/poi/xdgf/usermodel/XDGFSheet.java
index ef363efc8e..11621ded35 100644
--- a/poi-ooxml/src/main/java/org/apache/poi/xdgf/usermodel/XDGFSheet.java
+++ b/poi-ooxml/src/main/java/org/apache/poi/xdgf/usermodel/XDGFSheet.java
@@ -73,9 +73,9 @@ public abstract class XDGFSheet {
 
             for (SectionType section: sheet.getSectionArray()) {
                 String name = section.getN();
-                if (name.equals("Geometry")) {
+                if ("Geometry".equals(name)) {
                     _geometry.put(section.getIX(), new GeometrySection(section, this));
-                } else if (name.equals("Character")) {
+                } else if ("Character".equals(name)) {
                     _character = new CharacterSection(section, this);
                 } else {
                     _sections.put(name, XDGFSection.load(section, this));
diff --git a/test-data/diagram/clusterfuzz-testcase-minimized-POIVisioFuzzer-5026516754628608.vsdx b/test-data/diagram/clusterfuzz-testcase-minimized-POIVisioFuzzer-5026516754628608.vsdx
new file mode 100644
index 0000000000..4cbf5eb42a
Binary files /dev/null and b/test-data/diagram/clusterfuzz-testcase-minimized-POIVisioFuzzer-5026516754628608.vsdx differ
diff --git a/test-data/spreadsheet/stress.xls b/test-data/spreadsheet/stress.xls
index 04046bd635..3baca6559b 100644
Binary files a/test-data/spreadsheet/stress.xls and b/test-data/spreadsheet/stress.xls differ