diff --git a/src/JsonSchema/Constraints/Drafts/Draft06/FormatConstraint.php b/src/JsonSchema/Constraints/Drafts/Draft06/FormatConstraint.php
index ec61b73b..d8cc0e00 100644
--- a/src/JsonSchema/Constraints/Drafts/Draft06/FormatConstraint.php
+++ b/src/JsonSchema/Constraints/Drafts/Draft06/FormatConstraint.php
@@ -125,7 +125,11 @@ public function check(&$value, $schema = null, ?JsonPointer $path = null, $i = n
 
     private function validateDateTime(string $datetime, string $format): bool
     {
-        $dt = \DateTime::createFromFormat($format, $datetime);
+        try {
+            $dt = \DateTime::createFromFormat($format, $datetime);
+        } catch (\Throwable $e) {
+            return false;
+        }
 
         if (!$dt) {
             return false;
diff --git a/src/JsonSchema/Constraints/Drafts/Draft07/FormatConstraint.php b/src/JsonSchema/Constraints/Drafts/Draft07/FormatConstraint.php
index 8ddc879d..fd5474b6 100644
--- a/src/JsonSchema/Constraints/Drafts/Draft07/FormatConstraint.php
+++ b/src/JsonSchema/Constraints/Drafts/Draft07/FormatConstraint.php
@@ -149,7 +149,12 @@ private function validateDateTime(string $datetime, string $format): bool
             $input = sprintf('%s59%s', substr($datetime, 0, 6), substr($datetime, 8));
         }
 
-        $dt = \DateTimeImmutable::createFromFormat($format, $input);
+        try {
+            $dt = \DateTimeImmutable::createFromFormat($format, $input);
+        } catch (\Throwable $e) {
+            return false;
+        }
+
         if (!$dt) {
             return false;
         }
diff --git a/src/JsonSchema/Constraints/Drafts/Draft2019/FormatConstraint.php b/src/JsonSchema/Constraints/Drafts/Draft2019/FormatConstraint.php
index 5fb47c87..419f3cb2 100644
--- a/src/JsonSchema/Constraints/Drafts/Draft2019/FormatConstraint.php
+++ b/src/JsonSchema/Constraints/Drafts/Draft2019/FormatConstraint.php
@@ -140,7 +140,12 @@ private function validateDateTime(string $datetime, string $format): bool
             $input = sprintf('%s59%s', substr($datetime, 0, 6), substr($datetime, 8));
         }
 
-        $dt = \DateTimeImmutable::createFromFormat($format, $input);
+        try {
+            $dt = \DateTimeImmutable::createFromFormat($format, $input);
+        } catch (\Throwable $e) {
+            return false;
+        }
+
         if (!$dt) {
             return false;
         }
diff --git a/src/JsonSchema/Constraints/FormatConstraint.php b/src/JsonSchema/Constraints/FormatConstraint.php
index c38488dd..20fdb207 100644
--- a/src/JsonSchema/Constraints/FormatConstraint.php
+++ b/src/JsonSchema/Constraints/FormatConstraint.php
@@ -154,7 +154,11 @@ public function check(&$element, $schema = null, ?JsonPointer $path = null, $i =
 
     protected function validateDateTime($datetime, $format)
     {
-        $dt = \DateTime::createFromFormat($format, (string) $datetime);
+        try {
+            $dt = \DateTime::createFromFormat($format, (string) $datetime);
+        } catch (\Throwable $e) {
+            return false;
+        }
 
         if (!$dt) {
             return false;
diff --git a/tests/Constraints/Draft06/FormatConstraintTest.php b/tests/Constraints/Draft06/FormatConstraintTest.php
new file mode 100644
index 00000000..7be2849d
--- /dev/null
+++ b/tests/Constraints/Draft06/FormatConstraintTest.php
@@ -0,0 +1,34 @@
+<?php
+
+declare(strict_types=1);
+
+namespace JsonSchema\Tests\Constraints\Draft06;
+
+use Generator;
+use JsonSchema\Constraints\Drafts\Draft06\FormatConstraint;
+use JsonSchema\Tests\Constraints\VeryBaseTestCase;
+
+class FormatConstraintTest extends VeryBaseTestCase
+{
+    /**
+     * @dataProvider getInvalidFormats
+     */
+    public function testInvalidFormat($string, $format): void
+    {
+        $validator = new FormatConstraint();
+        $schema = new \stdClass();
+        $schema->format = $format;
+
+        $validator->check($string, $schema);
+        $this->assertCount(1, $validator->getErrors(), 'Expected 1 error');
+    }
+
+    public function getInvalidFormats(): Generator
+    {
+        yield 'Date-time format with value containing null byte' => ["2020-01-01T12:34:56\x00", 'date-time'];
+
+        yield 'Date format with value containing null byte' => ["2020-01-01\x00", 'date'];
+
+        yield 'Time format with value containing null byte' => ["13:37:00\x00", 'time'];
+    }
+}
diff --git a/tests/Constraints/Draft07/FormatConstraintTest.php b/tests/Constraints/Draft07/FormatConstraintTest.php
new file mode 100644
index 00000000..fcf09b80
--- /dev/null
+++ b/tests/Constraints/Draft07/FormatConstraintTest.php
@@ -0,0 +1,34 @@
+<?php
+
+declare(strict_types=1);
+
+namespace JsonSchema\Tests\Constraints\Draft07;
+
+use Generator;
+use JsonSchema\Constraints\Drafts\Draft07\FormatConstraint;
+use JsonSchema\Tests\Constraints\VeryBaseTestCase;
+
+class FormatConstraintTest extends VeryBaseTestCase
+{
+    /**
+     * @dataProvider getInvalidFormats
+     */
+    public function testInvalidFormat($string, $format): void
+    {
+        $validator = new FormatConstraint();
+        $schema = new \stdClass();
+        $schema->format = $format;
+
+        $validator->check($string, $schema);
+        $this->assertCount(1, $validator->getErrors(), 'Expected 1 error');
+    }
+
+    public function getInvalidFormats(): Generator
+    {
+        yield 'Date-time format with value containing null byte' => ["2020-01-01T12:34:56\x00", 'date-time'];
+
+        yield 'Date format with value containing null byte' => ["2020-01-01\x00", 'date'];
+
+        yield 'Time format with value containing null byte' => ["13:37:00\x00", 'time'];
+    }
+}
diff --git a/tests/Constraints/Draft2019/FormatConstraintTest.php b/tests/Constraints/Draft2019/FormatConstraintTest.php
new file mode 100644
index 00000000..5c6b90d5
--- /dev/null
+++ b/tests/Constraints/Draft2019/FormatConstraintTest.php
@@ -0,0 +1,34 @@
+<?php
+
+declare(strict_types=1);
+
+namespace JsonSchema\Tests\Constraints\Draft2019;
+
+use Generator;
+use JsonSchema\Constraints\Drafts\Draft2019\FormatConstraint;
+use JsonSchema\Tests\Constraints\VeryBaseTestCase;
+
+class FormatConstraintTest extends VeryBaseTestCase
+{
+    /**
+     * @dataProvider getInvalidFormats
+     */
+    public function testInvalidFormat($string, $format): void
+    {
+        $validator = new FormatConstraint();
+        $schema = new \stdClass();
+        $schema->format = $format;
+
+        $validator->check($string, $schema);
+        $this->assertCount(1, $validator->getErrors(), 'Expected 1 error');
+    }
+
+    public function getInvalidFormats(): Generator
+    {
+        yield 'Date-time format with value containing null byte' => ["2020-01-01T12:34:56\x00", 'date-time'];
+
+        yield 'Date format with value containing null byte' => ["2020-01-01\x00", 'date'];
+
+        yield 'Time format with value containing null byte' => ["13:37:00\x00", 'time'];
+    }
+}
diff --git a/tests/Constraints/FormatTest.php b/tests/Constraints/FormatConstraintTest.php
similarity index 97%
rename from tests/Constraints/FormatTest.php
rename to tests/Constraints/FormatConstraintTest.php
index 72471054..948bfd31 100644
--- a/tests/Constraints/FormatTest.php
+++ b/tests/Constraints/FormatConstraintTest.php
@@ -8,7 +8,7 @@
 use JsonSchema\Constraints\Factory;
 use JsonSchema\Constraints\FormatConstraint;
 
-class FormatTest extends BaseTestCase
+class FormatConstraintTest extends BaseTestCase
 {
     /** @var bool */
     protected $validateSchema = true;
@@ -196,10 +196,12 @@ public function getInvalidFormats(): \Generator
         yield ['199-01-1', 'date'];
         yield ['2012-0-11', 'date'];
         yield ['2012-10-1', 'date'];
+        yield 'Date format with value containing null byte' => ["2020-01-01\x00", 'date'];
 
         yield ['24:01:00', 'time'];
         yield ['00:00:60', 'time'];
         yield ['25:00:00', 'time'];
+        yield 'Time format with value containing null byte' => ["13:37:00\x00", 'time'];
 
         yield ['invalid_value_2000-05-01T12:12:12Z', 'date-time'];
         yield ['2000-05-01T12:12:12Z_invalid_value', 'date-time'];