diff --git a/ext/openssl/History.md b/ext/openssl/History.md
index ad3417f9d0..ecc53fad3b 100644
--- a/ext/openssl/History.md
+++ b/ext/openssl/History.md
@@ -1,3 +1,9 @@
+Version 3.3.1
+=============
+
+Merged changes in 3.1.2 and 3.2.2.
+
+
 Version 3.3.0
 =============
 
@@ -74,6 +80,12 @@ And various non-user-visible changes and bug fixes. Please see the commit
 history for more details.
 
 
+Version 3.2.2
+=============
+
+Merged changes in 3.1.2.
+
+
 Version 3.2.1
 =============
 
@@ -120,6 +132,23 @@ Notable changes
   [[GitHub #141]](https://github.com/ruby/openssl/pull/141)
 
 
+Version 3.1.2
+=============
+
+Bug fixes
+---------
+
+* Fix crash when attempting to export an incomplete `OpenSSL::PKey::DSA` key.
+  [[GitHub #845]](https://github.com/ruby/openssl/issues/845)
+  [[GitHub #847]](https://github.com/ruby/openssl/pull/847)
+* Remove the `OpenSSL::X509::V_FLAG_CRL_CHECK_ALL` flag from the default store
+  used by `OpenSSL::SSL::SSLContext#set_params`. It causes certificate
+  verification to fail with OpenSSL 3.6.0. It has no effect with any other
+  OpenSSL versions.
+  [[GitHub #949]](https://github.com/ruby/openssl/issues/949)
+  [[GitHub #950]](https://github.com/ruby/openssl/pull/950)
+
+
 Version 3.1.1
 =============
 
diff --git a/ext/openssl/extconf.rb b/ext/openssl/extconf.rb
index 2fcac85e68..adca064904 100644
--- a/ext/openssl/extconf.rb
+++ b/ext/openssl/extconf.rb
@@ -40,7 +40,7 @@ Logging::message "=== OpenSSL for Ruby configurator ===\n"
 
 $defs.push("-D""OPENSSL_SUPPRESS_DEPRECATED")
 
-have_func("rb_io_descriptor", "ruby/io.h")
+have_func("rb_io_descriptor")
 have_func("rb_io_maybe_wait(0, Qnil, Qnil, Qnil)", "ruby/io.h") # Ruby 3.1
 have_func("rb_io_timeout", "ruby/io.h")
 
diff --git a/ext/openssl/lib/openssl/ssl.rb b/ext/openssl/lib/openssl/ssl.rb
index d6cb260f9a..72ad37aec0 100644
--- a/ext/openssl/lib/openssl/ssl.rb
+++ b/ext/openssl/lib/openssl/ssl.rb
@@ -92,7 +92,6 @@ ssbzSibBsu/6iGtCOGEoXJf//////////wIBAg==
 
       DEFAULT_CERT_STORE = OpenSSL::X509::Store.new # :nodoc:
       DEFAULT_CERT_STORE.set_default_paths
-      DEFAULT_CERT_STORE.flags = OpenSSL::X509::V_FLAG_CRL_CHECK_ALL
 
       # A callback invoked when DH parameters are required for ephemeral DH key
       # exchange.
diff --git a/ext/openssl/lib/openssl/version.rb b/ext/openssl/lib/openssl/version.rb
index 3398fe39cc..8672154c89 100644
--- a/ext/openssl/lib/openssl/version.rb
+++ b/ext/openssl/lib/openssl/version.rb
@@ -1,5 +1,5 @@
 # frozen_string_literal: true
 
 module OpenSSL
-  VERSION = "3.3.0"
+  VERSION = "3.3.1"
 end
diff --git a/ext/openssl/openssl.gemspec b/ext/openssl/openssl.gemspec
index 9f7c718592..732007d8a9 100644
--- a/ext/openssl/openssl.gemspec
+++ b/ext/openssl/openssl.gemspec
@@ -1,6 +1,6 @@
 Gem::Specification.new do |spec|
   spec.name          = "openssl"
-  spec.version       = "3.3.0"
+  spec.version       = "3.3.1"
   spec.authors       = ["Martin Bosslet", "SHIBATA Hiroshi", "Zachary Scott", "Kazuki Yamaguchi"]
   spec.email         = ["ruby-core@ruby-lang.org"]
   spec.summary       = %q{SSL/TLS and general-purpose cryptography for Ruby}
diff --git a/ext/openssl/ossl_pkey.c b/ext/openssl/ossl_pkey.c
index 6af2245f39..3e1f1e603b 100644
--- a/ext/openssl/ossl_pkey.c
+++ b/ext/openssl/ossl_pkey.c
@@ -937,6 +937,7 @@ ossl_pkey_export_spki(VALUE self, int to_der)
     BIO *bio;
 
     GetPKey(self, pkey);
+    ossl_pkey_check_public_key(pkey);
     bio = BIO_new(BIO_s_mem());
     if (!bio)
 	ossl_raise(ePKeyError, "BIO_new");
diff --git a/ext/openssl/ossl_ssl.c b/ext/openssl/ossl_ssl.c
index 2525d0c872..b0980d4bba 100644
--- a/ext/openssl/ossl_ssl.c
+++ b/ext/openssl/ossl_ssl.c
@@ -1959,9 +1959,10 @@ ossl_ssl_read_internal(int argc, VALUE *argv, VALUE self, int nonblock)
 
     VALUE io = rb_attr_get(self, id_i_io);
 
-    rb_str_locktmp(str);
     for (;;) {
+        rb_str_locktmp(str);
         int nread = SSL_read(ssl, RSTRING_PTR(str), ilen);
+        rb_str_unlocktmp(str);
 
         cb_state = rb_attr_get(self, ID_callback_state);
         if (!NIL_P(cb_state)) {
@@ -1972,32 +1973,27 @@ ossl_ssl_read_internal(int argc, VALUE *argv, VALUE self, int nonblock)
 
         switch (ssl_get_error(ssl, nread)) {
           case SSL_ERROR_NONE:
-            rb_str_unlocktmp(str);
             rb_str_set_len(str, nread);
             return str;
           case SSL_ERROR_ZERO_RETURN:
-            rb_str_unlocktmp(str);
             if (no_exception_p(opts)) { return Qnil; }
             rb_eof_error();
           case SSL_ERROR_WANT_WRITE:
             if (nonblock) {
-                rb_str_unlocktmp(str);
                 if (no_exception_p(opts)) { return sym_wait_writable; }
                 write_would_block(nonblock);
             }
             io_wait_writable(io);
-            continue;
+            break;
           case SSL_ERROR_WANT_READ:
             if (nonblock) {
-                rb_str_unlocktmp(str);
                 if (no_exception_p(opts)) { return sym_wait_readable; }
                 read_would_block(nonblock);
             }
             io_wait_readable(io);
-            continue;
+            break;
           case SSL_ERROR_SYSCALL:
             if (!ERR_peek_error()) {
-                rb_str_unlocktmp(str);
                 if (errno)
                     rb_sys_fail(0);
                 else {
@@ -2014,9 +2010,13 @@ ossl_ssl_read_internal(int argc, VALUE *argv, VALUE self, int nonblock)
             }
             /* fall through */
           default:
-            rb_str_unlocktmp(str);
             ossl_raise(eSSLError, "SSL_read");
         }
+
+        // Ensure the buffer is not modified during io_wait_*able()
+        rb_str_modify(str);
+        if (rb_str_capacity(str) < (size_t)ilen)
+            rb_raise(eSSLError, "read buffer was modified");
     }
 }
 
diff --git a/test/openssl/test_bn.rb b/test/openssl/test_bn.rb
index 1217f250a7..457af41014 100644
--- a/test/openssl/test_bn.rb
+++ b/test/openssl/test_bn.rb
@@ -343,28 +343,36 @@ class OpenSSL::TestBN < OpenSSL::TestCase
     assert_equal(4, e.get_flags(OpenSSL::BN::CONSTTIME))
   end
 
-  if respond_to?(:ractor)
+  if defined?(Ractor) && respond_to?(:ractor)
+    unless Ractor.method_defined?(:value) # Ruby 3.4 or earlier
+      using Module.new {
+        refine Ractor do
+          alias value take
+        end
+      }
+    end
+
     ractor
     def test_ractor
-      assert_equal(@e1, Ractor.new { OpenSSL::BN.new("999") }.take)
-      assert_equal(@e3, Ractor.new { OpenSSL::BN.new("\a\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF", 2) }.take)
-      assert_equal("999", Ractor.new(@e1) { |e1| e1.to_s }.take)
-      assert_equal("07FFFFFFFFFFFFFFFFFFFFFFFFFF", Ractor.new(@e3) { |e3| e3.to_s(16) }.take)
-      assert_equal(2**107-1, Ractor.new(@e3) { _1.to_i }.take)
-      assert_equal([1000, -999], Ractor.new(@e2) { _1.coerce(1000) }.take)
-      assert_equal(false, Ractor.new  { 1.to_bn.zero? }.take)
-      assert_equal(true, Ractor.new { 1.to_bn.one? }.take)
-      assert_equal(true, Ractor.new(@e2) { _1.negative? }.take)
-      assert_equal("-03E7", Ractor.new(@e2) { _1.to_s(16) }.take)
-      assert_equal(2**107-1, Ractor.new(@e3) { _1.to_i }.take)
-      assert_equal([1000, -999], Ractor.new(@e2) { _1.coerce(1000) }.take)
-      assert_equal(true, Ractor.new { 0.to_bn.zero? }.take)
-      assert_equal(true, Ractor.new { 1.to_bn.one? }.take )
-      assert_equal(false,Ractor.new { 2.to_bn.odd? }.take)
-      assert_equal(true, Ractor.new(@e2) { _1.negative? }.take)
-      assert_include(128..255, Ractor.new { OpenSSL::BN.rand(8)}.take)
-      assert_include(0...2**32, Ractor.new { OpenSSL::BN.generate_prime(32) }.take)
-      assert_equal(0, Ractor.new { OpenSSL::BN.new(999).get_flags(OpenSSL::BN::CONSTTIME) }.take)
+      assert_equal(@e1, Ractor.new { OpenSSL::BN.new("999") }.value)
+      assert_equal(@e3, Ractor.new { OpenSSL::BN.new("\a\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF", 2) }.value)
+      assert_equal("999", Ractor.new(@e1) { |e1| e1.to_s }.value)
+      assert_equal("07FFFFFFFFFFFFFFFFFFFFFFFFFF", Ractor.new(@e3) { |e3| e3.to_s(16) }.value)
+      assert_equal(2**107-1, Ractor.new(@e3) { _1.to_i }.value)
+      assert_equal([1000, -999], Ractor.new(@e2) { _1.coerce(1000) }.value)
+      assert_equal(false, Ractor.new  { 1.to_bn.zero? }.value)
+      assert_equal(true, Ractor.new { 1.to_bn.one? }.value)
+      assert_equal(true, Ractor.new(@e2) { _1.negative? }.value)
+      assert_equal("-03E7", Ractor.new(@e2) { _1.to_s(16) }.value)
+      assert_equal(2**107-1, Ractor.new(@e3) { _1.to_i }.value)
+      assert_equal([1000, -999], Ractor.new(@e2) { _1.coerce(1000) }.value)
+      assert_equal(true, Ractor.new { 0.to_bn.zero? }.value)
+      assert_equal(true, Ractor.new { 1.to_bn.one? }.value )
+      assert_equal(false,Ractor.new { 2.to_bn.odd? }.value)
+      assert_equal(true, Ractor.new(@e2) { _1.negative? }.value)
+      assert_include(128..255, Ractor.new { OpenSSL::BN.rand(8)}.value)
+      assert_include(0...2**32, Ractor.new { OpenSSL::BN.generate_prime(32) }.value)
+      assert_equal(0, Ractor.new { OpenSSL::BN.new(999).get_flags(OpenSSL::BN::CONSTTIME) }.value)
       # test if shareable when frozen
       assert Ractor.shareable?(@e1.freeze)
     end
diff --git a/test/openssl/test_ossl.rb b/test/openssl/test_ossl.rb
index 3a90ead10a..9f4b39d4f5 100644
--- a/test/openssl/test_ossl.rb
+++ b/test/openssl/test_ossl.rb
@@ -42,12 +42,6 @@ class OpenSSL::OSSL < OpenSSL::SSLTestCase
   end
 
   def test_memcmp_timing
-    begin
-      require "benchmark"
-    rescue LoadError
-      pend "Benchmark is not available in this environment. Please install it with `gem install benchmark`."
-    end
-
     # Ensure using fixed_length_secure_compare takes almost exactly the same amount of time to compare two different strings.
     # Regular string comparison will short-circuit on the first non-matching character, failing this test.
     # NOTE: this test may be susceptible to noise if the system running the tests is otherwise under load.
@@ -58,8 +52,14 @@ class OpenSSL::OSSL < OpenSSL::SSLTestCase
 
     a_b_time = a_c_time = 0
     100.times do
-      a_b_time += Benchmark.measure { 100.times { OpenSSL.fixed_length_secure_compare(a, b) } }.real
-      a_c_time += Benchmark.measure { 100.times { OpenSSL.fixed_length_secure_compare(a, c) } }.real
+      t1 = Process.clock_gettime(Process::CLOCK_MONOTONIC)
+      100.times { OpenSSL.fixed_length_secure_compare(a, b) }
+      t2 = Process.clock_gettime(Process::CLOCK_MONOTONIC)
+      100.times { OpenSSL.fixed_length_secure_compare(a, c) }
+      t3 = Process.clock_gettime(Process::CLOCK_MONOTONIC)
+
+      a_b_time += t2 - t1
+      a_c_time += t3 - t2
     end
     assert_operator(a_b_time, :<, a_c_time * 10, "fixed_length_secure_compare timing test failed")
     assert_operator(a_c_time, :<, a_b_time * 10, "fixed_length_secure_compare timing test failed")
diff --git a/test/openssl/test_pkey_dsa.rb b/test/openssl/test_pkey_dsa.rb
index 3e8a83b2d0..cdaa8b32d4 100644
--- a/test/openssl/test_pkey_dsa.rb
+++ b/test/openssl/test_pkey_dsa.rb
@@ -33,6 +33,12 @@ class OpenSSL::TestPKeyDSA < OpenSSL::PKeyTestCase
     end
   end
 
+  def test_new_empty
+    key = OpenSSL::PKey::DSA.new
+    assert_nil(key.p)
+    assert_raise(OpenSSL::PKey::PKeyError) { key.to_der }
+  end
+
   def test_generate
     # DSA.generate used to call DSA_generate_parameters_ex(), which adjusts the
     # size of q according to the size of p
diff --git a/test/openssl/test_ssl.rb b/test/openssl/test_ssl.rb
index 459efcc18e..225dd19e09 100644
--- a/test/openssl/test_ssl.rb
+++ b/test/openssl/test_ssl.rb
@@ -256,11 +256,16 @@ class OpenSSL::TestSSL < OpenSSL::SSLTestCase
         ssl.syswrite(str)
         assert_equal(str, ssl.sysread(str.bytesize))
 
-        ssl.timeout = 1
-        assert_raise(IO::TimeoutError) {ssl.read(1)}
+        ssl.timeout = 0.1
+        assert_raise(IO::TimeoutError) { ssl.sysread(1) }
 
         ssl.syswrite(str)
         assert_equal(str, ssl.sysread(str.bytesize))
+
+        buf = "orig".b
+        assert_raise(IO::TimeoutError) { ssl.sysread(1, buf) }
+        assert_equal("orig", buf)
+        assert_nothing_raised { buf.clear }
       end
     end
   end