diff --git a/patch/patch.cfg b/patch/patch.cfg
index 467aa88f0..7e27525c1 100644
--- a/patch/patch.cfg
+++ b/patch/patch.cfg
@@ -512,6 +512,10 @@ patches = [
     # win: Add SHA256 implementation for Sid::FromNamedCapability using the
     # Crypto API.
     # https://github.com/chromiumembedded/cef/issues/3791
+    #
+    # win: Disable use of Rust for JSON parsing with cef_sandbox.
+    # Enables the fallback to C++ that was removed in
+    # https://crrev.com/9ddc1624637c8cfa8ef50a95abd779e0ba4d67f6
     'name': 'base_sandbox_2743',
   },
   {
diff --git a/patch/patches/base_sandbox_2743.patch b/patch/patches/base_sandbox_2743.patch
index 2a817812b..5c2be268d 100644
--- a/patch/patches/base_sandbox_2743.patch
+++ b/patch/patches/base_sandbox_2743.patch
@@ -87,6 +87,116 @@ index 2158b648ca58a..8a8cb13b2fd74 100644
  #include "base/hash/sha1_nacl.h"
  #else
  #include "base/hash/sha1_boringssl.h"
+diff --git base/json/json_reader.cc base/json/json_reader.cc
+index b3db0dea0fff6..e53ff0049559a 100644
+--- base/json/json_reader.cc
++++ base/json/json_reader.cc
+@@ -12,8 +12,9 @@
+ #include "base/logging.h"
+ #include "base/metrics/histogram_macros.h"
+ #include "build/build_config.h"
++#include "cef/libcef/features/features.h"
+ 
+-#if !BUILDFLAG(IS_NACL)
++#if !(BUILDFLAG(IS_NACL) || BUILDFLAG(IS_CEF_SANDBOX_BUILD))
+ #include "base/strings/string_view_rust.h"
+ #include "third_party/rust/serde_json_lenient/v0_2/wrapper/functions.h"
+ #include "third_party/rust/serde_json_lenient/v0_2/wrapper/lib.rs.h"
+@@ -23,7 +24,7 @@ namespace base {
+ 
+ // TODO(crbug.com/40811643): Move the C++ parser into components/nacl to just
+ // run in-process there. Don't compile base::JSONReader on NaCL at all.
+-#if !BUILDFLAG(IS_NACL)
++#if !(BUILDFLAG(IS_NACL) || BUILDFLAG(IS_CEF_SANDBOX_BUILD))
+ 
+ namespace {
+ using serde_json_lenient::ContextPointer;
+@@ -134,16 +135,16 @@ JSONReader::Result DecodeJSONInRust(std::string_view json,
+ 
+ }  // anonymous namespace
+ 
+-#endif  // !BUILDFLAG(IS_NACL)
++#endif  // !(BUILDFLAG(IS_NACL) || BUILDFLAG(IS_CEF_SANDBOX_BUILD))
+ 
+ // static
+ std::optional<Value> JSONReader::Read(std::string_view json,
+                                       int options,
+                                       size_t max_depth) {
+-#if BUILDFLAG(IS_NACL)
++#if (BUILDFLAG(IS_NACL) || BUILDFLAG(IS_CEF_SANDBOX_BUILD))
+   internal::JSONParser parser(options, max_depth);
+   return parser.Parse(json);
+-#else   // BUILDFLAG(IS_NACL)
++#else   // (BUILDFLAG(IS_NACL) || BUILDFLAG(IS_CEF_SANDBOX_BUILD))
+   SCOPED_UMA_HISTOGRAM_TIMER_MICROS(kSecurityJsonParsingTime);
+   if (UsingRust()) {
+     JSONReader::Result result = DecodeJSONInRust(json, options, max_depth);
+@@ -155,7 +156,7 @@ std::optional<Value> JSONReader::Read(std::string_view json,
+     internal::JSONParser parser(options, max_depth);
+     return parser.Parse(json);
+   }
+-#endif  // BUILDFLAG(IS_NACL)
++#endif  // (BUILDFLAG(IS_NACL) || BUILDFLAG(IS_CEF_SANDBOX_BUILD))
+ }
+ 
+ // static
+@@ -173,7 +174,7 @@ std::optional<Value::Dict> JSONReader::ReadDict(std::string_view json,
+ JSONReader::Result JSONReader::ReadAndReturnValueWithError(
+     std::string_view json,
+     int options) {
+-#if BUILDFLAG(IS_NACL)
++#if (BUILDFLAG(IS_NACL) || BUILDFLAG(IS_CEF_SANDBOX_BUILD))
+   internal::JSONParser parser(options);
+   auto value = parser.Parse(json);
+   if (!value) {
+@@ -185,7 +186,7 @@ JSONReader::Result JSONReader::ReadAndReturnValueWithError(
+   }
+ 
+   return std::move(*value);
+-#else   // BUILDFLAG(IS_NACL)
++#else   // (BUILDFLAG(IS_NACL) || BUILDFLAG(IS_CEF_SANDBOX_BUILD))
+   SCOPED_UMA_HISTOGRAM_TIMER_MICROS(kSecurityJsonParsingTime);
+   if (UsingRust()) {
+     return DecodeJSONInRust(json, options, internal::kAbsoluteMaxDepth);
+@@ -202,7 +203,7 @@ JSONReader::Result JSONReader::ReadAndReturnValueWithError(
+ 
+     return std::move(*value);
+   }
+-#endif  // BUILDFLAG(IS_NACL)
++#endif  // (BUILDFLAG(IS_NACL) || BUILDFLAG(IS_CEF_SANDBOX_BUILD))
+ }
+ 
+ // static
+@@ -213,7 +214,7 @@ bool JSONReader::UsingRust() {
+   if (!base::FeatureList::GetInstance()) {
+     return false;
+   }
+-#if BUILDFLAG(IS_NACL)
++#if (BUILDFLAG(IS_NACL) || BUILDFLAG(IS_CEF_SANDBOX_BUILD))
+   return false;
+ #else
+   return base::FeatureList::IsEnabled(base::features::kUseRustJsonParser);
+diff --git base/logging.cc base/logging.cc
+index 508ce135131aa..4158b7d5273b0 100644
+--- base/logging.cc
++++ base/logging.cc
+@@ -60,6 +60,7 @@
+ #include "base/vlog.h"
+ #include "build/build_config.h"
+ #include "build/chromeos_buildflags.h"
++#include "cef/libcef/features/features.h"
+ #include "third_party/abseil-cpp/absl/base/internal/raw_logging.h"
+ #include "third_party/abseil-cpp/absl/cleanup/cleanup.h"
+ 
+@@ -526,7 +527,7 @@ bool BaseInitLoggingImpl(const LoggingSettings& settings) {
+   }
+ #endif
+ 
+-#if !BUILDFLAG(IS_NACL)
++#if !BUILDFLAG(IS_NACL) && !BUILDFLAG(IS_CEF_SANDBOX_BUILD)
+   // Connects Rust logging with the //base logging functionality.
+   internal::init_rust_log_crate();
+ #endif
 diff --git base/metrics/crc32.cc base/metrics/crc32.cc
 index 83e3cee2579ab..8238767ab9126 100644
 --- base/metrics/crc32.cc
diff --git a/tools/gn_args.py b/tools/gn_args.py
index 9173c60c5..6d0c3a73c 100644
--- a/tools/gn_args.py
+++ b/tools/gn_args.py
@@ -544,10 +544,6 @@ def GetConfigArgsSandbox(platform, args, is_debug, cpu):
       # Enable base target customizations necessary for distribution of the
       # cef_sandbox static library.
       'is_cef_sandbox_build': True,
-
-      # Disable use of rust for JSON parsing. This avoids a dependency on
-      # rust libraries.
-      'enable_rust_json': False,
   }
 
   if platform == 'windows':