diff --git a/deps/zlib/contrib/bench/zlib_bench.cc b/deps/zlib/contrib/bench/zlib_bench.cc
index b65f9291bff500..6df296c8721056 100644
--- a/deps/zlib/contrib/bench/zlib_bench.cc
+++ b/deps/zlib/contrib/bench/zlib_bench.cc
@@ -71,10 +71,6 @@ Data read_file_data_or_exit(const char* name) {
   return data;
 }
 
-size_t zlib_estimate_compressed_size(size_t input_size) {
-  return compressBound(input_size);
-}
-
 enum zlib_wrapper {
   kWrapperNONE,
   kWrapperZLIB,
@@ -128,10 +124,6 @@ void zlib_compress(
     std::string* output,
     bool resize_output = false)
 {
-  if (resize_output)
-    output->resize(zlib_estimate_compressed_size(input_size));
-  size_t output_size = output->size();
-
   z_stream stream;
   memset(&stream, 0, sizeof(stream));
 
@@ -140,6 +132,11 @@ void zlib_compress(
   if (result != Z_OK)
     error_exit("deflateInit2 failed", result);
 
+  if (resize_output) {
+    output->resize(deflateBound(&stream, input_size));
+  }
+  size_t output_size = output->size();
+
   stream.next_out = (Bytef*)string_data(output);
   stream.avail_out = (uInt)output_size;
   stream.next_in = (z_const Bytef*)input;
@@ -299,7 +296,7 @@ void zlib_file(const char* name,
 
     // Pre-grow the output buffer so we don't measure string resize time.
     for (int b = 0; b < blocks; ++b)
-      compressed[b].resize(zlib_estimate_compressed_size(block_size));
+      zlib_compress(type, input[b], input_length[b], &compressed[b], true);
 
     auto start = now();
     for (int b = 0; b < blocks; ++b)
@@ -307,11 +304,6 @@ void zlib_file(const char* name,
         zlib_compress(type, input[b], input_length[b], &compressed[b]);
     ctime[run] = std::chrono::duration<double>(now() - start).count();
 
-    // Compress again, resizing compressed, so we don't leave junk at the
-    // end of the compressed string that could confuse zlib_uncompress().
-    for (int b = 0; b < blocks; ++b)
-      zlib_compress(type, input[b], input_length[b], &compressed[b], true);
-
     for (int b = 0; b < blocks; ++b)
       output[b].resize(input_length[b]);
 
diff --git a/deps/zlib/contrib/tests/fuzzers/BUILD.gn b/deps/zlib/contrib/tests/fuzzers/BUILD.gn
index 16e918a720ece9..d7db4b3459bae2 100644
--- a/deps/zlib/contrib/tests/fuzzers/BUILD.gn
+++ b/deps/zlib/contrib/tests/fuzzers/BUILD.gn
@@ -34,6 +34,11 @@ fuzzer_test("zlib_deflate_set_dictionary_fuzzer") {
   deps = [ "../../../:zlib" ]
 }
 
+fuzzer_test("zlib_compress_fuzzer") {
+  sources = [ "compress_fuzzer.cc" ]
+  deps = [ "../../../:zlib" ]
+}
+
 fuzzer_test("zlib_deflate_fuzzer") {
   sources = [ "deflate_fuzzer.cc" ]
   deps = [ "../../../:zlib" ]
diff --git a/deps/zlib/contrib/tests/fuzzers/compress_fuzzer.cc b/deps/zlib/contrib/tests/fuzzers/compress_fuzzer.cc
new file mode 100644
index 00000000000000..3afc78122be2ba
--- /dev/null
+++ b/deps/zlib/contrib/tests/fuzzers/compress_fuzzer.cc
@@ -0,0 +1,46 @@
+// Copyright 2024 The Chromium Authors
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include <fuzzer/FuzzedDataProvider.h>
+
+#include <vector>
+
+#include "zlib.h"
+
+// Fuzzer builds often have NDEBUG set, so roll our own assert macro.
+#define ASSERT(cond)                                                           \
+  do {                                                                         \
+    if (!(cond)) {                                                             \
+      fprintf(stderr, "%s:%d Assert failed: %s\n", __FILE__, __LINE__, #cond); \
+      exit(1);                                                                 \
+    }                                                                          \
+  } while (0)
+
+extern "C" int LLVMFuzzerTestOneInput(const uint8_t* data, size_t size) {
+  FuzzedDataProvider fdp(data, size);
+  const int level = fdp.PickValueInArray({-1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9});
+  const std::vector<uint8_t> src = fdp.ConsumeRemainingBytes<uint8_t>();
+
+  const unsigned long compress_bound = compressBound(src.size());
+  std::vector<uint8_t> compressed;
+  compressed.resize(compress_bound);
+
+  unsigned long compressed_size = compress_bound;
+  int ret = compress2(compressed.data(), &compressed_size, src.data(),
+                      src.size(), level);
+  ASSERT(ret == Z_OK);
+  ASSERT(compressed_size <= compress_bound);
+  compressed.resize(compressed_size);
+
+  std::vector<uint8_t> uncompressed;
+  uncompressed.resize(src.size());
+  unsigned long uncompressed_size = uncompressed.size();
+  ret = uncompress(uncompressed.data(), &uncompressed_size, compressed.data(),
+                   compressed.size());
+  ASSERT(ret == Z_OK);
+  ASSERT(uncompressed_size == src.size());
+  ASSERT(uncompressed == src);
+
+  return 0;
+}
diff --git a/src/zlib_version.h b/src/zlib_version.h
index 40a715aa6c0d05..1c55a4e5015297 100644
--- a/src/zlib_version.h
+++ b/src/zlib_version.h
@@ -2,5 +2,5 @@
 // Refer to tools/dep_updaters/update-zlib.sh
 #ifndef SRC_ZLIB_VERSION_H_
 #define SRC_ZLIB_VERSION_H_
-#define ZLIB_VERSION "1.3.0.1-motley-8b7eff8"
+#define ZLIB_VERSION "1.3.0.1-motley-68e57e6"
 #endif  // SRC_ZLIB_VERSION_H_