diff --git a/.github/workflows/gradle-wrapper-validation.yml b/.github/workflows/gradle-wrapper-validation.yml
index 86ff6a7..fc22967 100644
--- a/.github/workflows/gradle-wrapper-validation.yml
+++ b/.github/workflows/gradle-wrapper-validation.yml
@@ -11,5 +11,5 @@ jobs:
     name: "Validation"
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4
-      - uses: gradle/wrapper-validation-action@v3
+      - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
+      - uses: gradle/actions/wrapper-validation@3f5f9adaf7d9fecd50b5935e54106014257a94e6 # v6.4.0
diff --git a/.github/workflows/gradle.yml b/.github/workflows/gradle.yml
index e414393..ab97bbd 100644
--- a/.github/workflows/gradle.yml
+++ b/.github/workflows/gradle.yml
@@ -11,12 +11,12 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        java: [ '17', '21', '25' ]
+        java: [ '21', '25', '27' ]
 
     steps:
-    - uses: actions/checkout@v4
+    - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
     - name: Set up Java
-      uses: actions/setup-java@v4
+      uses: actions/setup-java@b843ebf9b913146b38da2eaa7aeddf76074ae1ad # v6.1.0
       with:
         java-version: ${{ matrix.java }}
         distribution: 'temurin'
diff --git a/build.gradle.kts b/build.gradle.kts
index 26178db..c42c9c5 100644
--- a/build.gradle.kts
+++ b/build.gradle.kts
@@ -1,8 +1,9 @@
 buildscript {
     configurations.classpath {
         resolutionStrategy {
+            // JGit 7.x removed GpgObjectSigner which JReleaser still depends on
             // Fix https://github.com/jreleaser/jreleaser/issues/1643
-            force("org.eclipse.jgit:org.eclipse.jgit:5.13.0.202109080827-r")
+            force("org.eclipse.jgit:org.eclipse.jgit:6.10.0.202406032230-r")
         }
     }
 }
@@ -12,7 +13,7 @@ plugins {
     `maven-publish`
     signing
     id("com.diffplug.spotless") version "latest.release"
-    id("org.jreleaser") version "1.24.0"
+    id("org.jreleaser") version "1.26.0"
 }
 
 repositories {
@@ -20,8 +21,8 @@ repositories {
 }
 
 java {
-    sourceCompatibility = JavaVersion.VERSION_17
-    targetCompatibility = JavaVersion.VERSION_17
+    sourceCompatibility = JavaVersion.VERSION_21
+    targetCompatibility = JavaVersion.VERSION_21
     withSourcesJar()
     withJavadocJar()
 }
@@ -140,7 +141,7 @@ spotless {
 }
 
 tasks.wrapper {
-    gradleVersion = "9.5.0"
+    gradleVersion = "9.8.1"
     distributionType = Wrapper.DistributionType.ALL
 }
 
diff --git a/configuration-test/build.gradle.kts b/configuration-test/build.gradle.kts
index 50208f0..8c0cf20 100644
--- a/configuration-test/build.gradle.kts
+++ b/configuration-test/build.gradle.kts
@@ -6,8 +6,8 @@ group = "de.cronn"
 version = "0.0.1-SNAPSHOT"
 
 java {
-    sourceCompatibility = JavaVersion.VERSION_17
-    targetCompatibility = JavaVersion.VERSION_17
+    sourceCompatibility = JavaVersion.VERSION_21
+    targetCompatibility = JavaVersion.VERSION_21
     withSourcesJar()
     withJavadocJar()
 }
diff --git a/data/test/validation/MarkdownTableTest_shouldPadCellsContainingWideCharacters.md b/data/test/validation/MarkdownTableTest_shouldPadCellsContainingWideCharacters.md
new file mode 100644
index 0000000..276864e
--- /dev/null
+++ b/data/test/validation/MarkdownTableTest_shouldPadCellsContainingWideCharacters.md
@@ -0,0 +1,5 @@
+| location                | correct |
+|-------------------------|---------|
+| Sanku Maots'ai 三顾冒菜 | ✅      |
+| Café                    | ❌      |
+| Café                    | ❤️      |
diff --git a/data/test/validation/MarkdownTableTest_shouldRenderCellsContainingPipesAndLineBreaks.md b/data/test/validation/MarkdownTableTest_shouldRenderCellsContainingPipesAndLineBreaks.md
new file mode 100644
index 0000000..f7a5f30
--- /dev/null
+++ b/data/test/validation/MarkdownTableTest_shouldRenderCellsContainingPipesAndLineBreaks.md
@@ -0,0 +1,4 @@
+| text                        |
+|-----------------------------|
+| Maotsai 31.9/kg \| 0.392 kg |
+| first line<br>second line   |
diff --git a/gradle.lockfile b/gradle.lockfile
index a9224f1..cc0c831 100644
--- a/gradle.lockfile
+++ b/gradle.lockfile
@@ -1,11 +1,11 @@
 # This is a Gradle generated file for dependency locking.
 # Manual edits can break the build and are not advised.
 # This file is expected to be part of source control.
-com.fasterxml.jackson.core:jackson-annotations:2.21=testCompileClasspath,testRuntimeClasspath
-com.fasterxml.jackson.core:jackson-core:2.21.3=testCompileClasspath,testRuntimeClasspath
-com.fasterxml.jackson.core:jackson-databind:2.21.3=testCompileClasspath,testRuntimeClasspath
-com.fasterxml.jackson.datatype:jackson-datatype-jsr310:2.21.3=testCompileClasspath,testRuntimeClasspath
-com.fasterxml.jackson:jackson-bom:2.21.3=testCompileClasspath,testRuntimeClasspath
+com.fasterxml.jackson.core:jackson-annotations:2.22=testCompileClasspath,testRuntimeClasspath
+com.fasterxml.jackson.core:jackson-core:2.22.3=testCompileClasspath,testRuntimeClasspath
+com.fasterxml.jackson.core:jackson-databind:2.22.3=testCompileClasspath,testRuntimeClasspath
+com.fasterxml.jackson.datatype:jackson-datatype-jsr310:2.22.3=testCompileClasspath,testRuntimeClasspath
+com.fasterxml.jackson:jackson-bom:2.22.3=testCompileClasspath,testRuntimeClasspath
 com.googlecode.java-diff-utils:diffutils:1.3.0=compileClasspath,runtimeClasspath,testCompileClasspath,testRuntimeClasspath
 net.bytebuddy:byte-buddy:1.18.3=testCompileClasspath,testRuntimeClasspath
 org.apiguardian:apiguardian-api:1.1.2=compileClasspath,testCompileClasspath
diff --git a/gradle/wrapper/gradle-wrapper.jar b/gradle/wrapper/gradle-wrapper.jar
index b1b8ef5..9fa7f28 100644
Binary files a/gradle/wrapper/gradle-wrapper.jar and b/gradle/wrapper/gradle-wrapper.jar differ
diff --git a/gradle/wrapper/gradle-wrapper.properties b/gradle/wrapper/gradle-wrapper.properties
index f193d72..0ce8225 100644
--- a/gradle/wrapper/gradle-wrapper.properties
+++ b/gradle/wrapper/gradle-wrapper.properties
@@ -1,6 +1,6 @@
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-9.5.0-all.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-9.8.1-all.zip
 networkTimeout=10000
 retries=0
 retryBackOffMs=500
diff --git a/gradlew b/gradlew
index b9bb139..249efbb 100755
--- a/gradlew
+++ b/gradlew
@@ -20,7 +20,7 @@
 
 ##############################################################################
 #
-#   Gradle start up script for POSIX generated by Gradle.
+#   gradlew start up script for POSIX generated by Gradle.
 #
 #   Important for running:
 #
@@ -29,7 +29,7 @@
 #       bash, then to run this script, type that shell name before the whole
 #       command line, like:
 #
-#           ksh Gradle
+#           ksh gradlew
 #
 #       Busybox and similar reduced shells will NOT work, because this script
 #       requires all of these POSIX shell features:
diff --git a/gradlew.bat b/gradlew.bat
index 24c62d5..3185a43 100644
--- a/gradlew.bat
+++ b/gradlew.bat
@@ -19,13 +19,40 @@
 @if "%DEBUG%"=="" @echo off
 @rem ##########################################################################
 @rem
-@rem  Gradle startup script for Windows
+@rem  gradlew startup script for Windows
 @rem
 @rem ##########################################################################
 
 @rem Set local scope for the variables, and ensure extensions are enabled
 setlocal EnableExtensions
 
+@rem Catch executions from older scripts and ensure they exit cleanly.
+@rem This can be removed once we can be reasonably confident that few people
+@rem will be migrating directly to this new wrapper.
+goto afterSafetyNet
+::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
+::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
+::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
+::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
+::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
+::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
+::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
+::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
+::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
+::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
+::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
+::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
+::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
+::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
+::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
+::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
+::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
+::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
+::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
+::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
+goto exitWithErrorLevel
+:afterSafetyNet
+
 set DIRNAME=%~dp0
 if "%DIRNAME%"=="" set DIRNAME=.
 @rem This is normally unused
@@ -45,13 +72,14 @@ set JAVA_EXE=java.exe
 %JAVA_EXE% -version >NUL 2>&1
 if %ERRORLEVEL% equ 0 goto execute
 
-echo. 1>&2
-echo ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH. 1>&2
-echo. 1>&2
-echo Please set the JAVA_HOME variable in your environment to match the 1>&2
-echo location of your Java installation. 1>&2
+1>&2 echo.
+1>&2 echo ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
+1>&2 echo.
+1>&2 echo Please set the JAVA_HOME variable in your environment to match the
+1>&2 echo location of your Java installation.
 
 "%COMSPEC%" /c exit 1
+goto exitWithErrorLevel
 
 :findJavaFromJavaHome
 set JAVA_HOME=%JAVA_HOME:"=%
@@ -59,24 +87,26 @@ set JAVA_EXE=%JAVA_HOME%/bin/java.exe
 
 if exist "%JAVA_EXE%" goto execute
 
-echo. 1>&2
-echo ERROR: JAVA_HOME is set to an invalid directory: %JAVA_HOME% 1>&2
-echo. 1>&2
-echo Please set the JAVA_HOME variable in your environment to match the 1>&2
-echo location of your Java installation. 1>&2
+1>&2 echo.
+1>&2 echo ERROR: JAVA_HOME is set to an invalid directory: %JAVA_HOME%
+1>&2 echo.
+1>&2 echo Please set the JAVA_HOME variable in your environment to match the
+1>&2 echo location of your Java installation.
 
 "%COMSPEC%" /c exit 1
+goto exitWithErrorLevel
 
 :execute
 @rem Setup the command line
 
 
 
-@rem Execute Gradle
+@rem Execute gradlew
 @rem endlocal doesn't take effect until after the line is parsed and variables are expanded
 @rem which allows us to clear the local environment before executing the java command
-endlocal & "%JAVA_EXE%" %DEFAULT_JVM_OPTS% %JAVA_OPTS% %GRADLE_OPTS% "-Dorg.gradle.appname=%APP_BASE_NAME%" -jar "%APP_HOME%\gradle\wrapper\gradle-wrapper.jar" %* & call :exitWithErrorLevel
+endlocal & "%JAVA_EXE%" %DEFAULT_JVM_OPTS% %JAVA_OPTS% %GRADLE_OPTS% "-Dorg.gradle.appname=%APP_BASE_NAME%" -jar "%APP_HOME%\gradle\wrapper\gradle-wrapper.jar" %* & call :exitWithErrorLevel & goto exitWithErrorLevel
 
+@rem This label must not be changed. We rely on old scripts being able to jump to this point.
 :exitWithErrorLevel
 @rem Use "%COMSPEC%" /c exit to allow operators to work properly in scripts
 "%COMSPEC%" /c exit %ERRORLEVEL%
diff --git a/src/main/java/de/cronn/assertions/validationfile/util/MarkdownTable.java b/src/main/java/de/cronn/assertions/validationfile/util/MarkdownTable.java
index f013ec1..825fe90 100644
--- a/src/main/java/de/cronn/assertions/validationfile/util/MarkdownTable.java
+++ b/src/main/java/de/cronn/assertions/validationfile/util/MarkdownTable.java
@@ -22,7 +22,12 @@ public MarkdownTable(List<String> header) {
   }
 
   public void addCell(Object value) {
-    currentRow.add(Objects.toString(value));
+    currentRow.add(escape(Objects.toString(value)));
+  }
+
+  // an unescaped pipe or line break would end the cell or the row
+  private static String escape(String value) {
+    return value.replace("|", "\\|").replace("\r\n", "<br>").replace("\n", "<br>");
   }
 
   public void addCells(Collection<? extends Object> values) {
@@ -98,10 +103,11 @@ public String toString() {
   }
 
   private List<Integer> computeColumnsWidths() {
-    List<Integer> widths = header.stream().map(String::length).collect(Collectors.toList());
+    List<Integer> widths =
+        header.stream().map(MarkdownTable::displayWidth).collect(Collectors.toList());
     for (int i = 0; i < header.size(); i++) {
       for (List<String> row : rows) {
-        widths.set(i, Math.max(row.get(i).length(), widths.get(i)));
+        widths.set(i, Math.max(displayWidth(row.get(i)), widths.get(i)));
       }
     }
     return widths;
@@ -116,7 +122,50 @@ private void repeat(char ch, int times, StringBuilder sb) {
   private void pad(String value, int size, StringBuilder sb) {
     sb.append(' ');
     sb.append(value);
-    repeat(' ', size - value.length(), sb);
+    repeat(' ', size - displayWidth(value), sb);
     sb.append(' ');
   }
+
+  /**
+   * Number of columns the value occupies in a monospace font: East Asian wide characters and emoji
+   * take two columns, combining marks and format characters (such as the zero width joiner) none.
+   */
+  static int displayWidth(String value) {
+    int width = 0;
+    int i = 0;
+    while (i < value.length()) {
+      int codePoint = value.codePointAt(i);
+      i += Character.charCount(codePoint);
+      if (isZeroWidth(codePoint)) {
+        continue;
+      }
+      boolean emojiPresentation =
+          i < value.length() && value.charAt(i) == EMOJI_PRESENTATION_SELECTOR;
+      width += isWide(codePoint) || emojiPresentation ? 2 : 1;
+    }
+    return width;
+  }
+
+  private static final char EMOJI_PRESENTATION_SELECTOR = '\uFE0F';
+
+  private static boolean isZeroWidth(int codePoint) {
+    int type = Character.getType(codePoint);
+    return type == Character.NON_SPACING_MARK
+        || type == Character.ENCLOSING_MARK
+        || type == Character.FORMAT;
+  }
+
+  // approximates East_Asian_Width W and F, which the JDK does not provide
+  private static boolean isWide(int codePoint) {
+    if (Character.isEmojiPresentation(codePoint)) {
+      return true;
+    }
+    return switch (Character.UnicodeScript.of(codePoint)) {
+      case HAN, HIRAGANA, KATAKANA, HANGUL, BOPOMOFO, YI -> true;
+      default ->
+          Character.UnicodeBlock.of(codePoint) == Character.UnicodeBlock.CJK_SYMBOLS_AND_PUNCTUATION
+              || (codePoint >= 0xFF01 && codePoint <= 0xFF60) // fullwidth forms
+              || (codePoint >= 0xFFE0 && codePoint <= 0xFFE6);
+    };
+  }
 }
diff --git a/src/test/java/de/cronn/assertions/validationfile/util/MarkdownTableTest.java b/src/test/java/de/cronn/assertions/validationfile/util/MarkdownTableTest.java
index 08b2cce..7360223 100644
--- a/src/test/java/de/cronn/assertions/validationfile/util/MarkdownTableTest.java
+++ b/src/test/java/de/cronn/assertions/validationfile/util/MarkdownTableTest.java
@@ -46,4 +46,36 @@ void shouldPadCells() {
                 + "| Countrywide Powdered Coatings Ltd |\n"
                 + "| Craft Textiles Ltd                |");
   }
+
+  @Test
+  void shouldPadCellsContainingWideCharacters() {
+    MarkdownTable markdownTable = new MarkdownTable(List.of("location", "correct"));
+    markdownTable.addRow("Sanku Maots'ai 三顾冒菜", "✅");
+    markdownTable.addRow("Café", "❌");
+    markdownTable.addRow("Cafe\u0301", "❤\uFE0F");
+
+    assertWithFile(markdownTable.toString(), FileExtensions.MD);
+  }
+
+  @Test
+  void shouldRenderCellsContainingPipesAndLineBreaks() {
+    MarkdownTable markdownTable = new MarkdownTable(List.of("text"));
+    markdownTable.addRow("Maotsai 31.9/kg | 0.392 kg");
+    markdownTable.addRow("first line\nsecond line");
+
+    assertWithFile(markdownTable.toString(), FileExtensions.MD);
+  }
+
+  @Test
+  void shouldComputeDisplayWidth() {
+    assertThat(MarkdownTable.displayWidth("abc")).isEqualTo(3);
+    assertThat(MarkdownTable.displayWidth("三顾冒菜")).isEqualTo(8);
+    assertThat(MarkdownTable.displayWidth("ＡＢ")).isEqualTo(4);
+    assertThat(MarkdownTable.displayWidth("한국어")).isEqualTo(6);
+    assertThat(MarkdownTable.displayWidth("✅❌")).isEqualTo(4);
+    assertThat(MarkdownTable.displayWidth("😀")).isEqualTo(2);
+    assertThat(MarkdownTable.displayWidth("✓✗")).isEqualTo(2);
+    assertThat(MarkdownTable.displayWidth("e\u0301")).isEqualTo(1);
+    assertThat(MarkdownTable.displayWidth("❤\uFE0F")).isEqualTo(2);
+  }
 }