diff --git a/meta/recipes-devtools/ruby/ruby/CVE-2024-43398.patch b/meta/recipes-devtools/ruby/ruby/CVE-2024-43398.patch
new file mode 100644
index 0000000000..02dc0a20be
--- /dev/null
+++ b/meta/recipes-devtools/ruby/ruby/CVE-2024-43398.patch
@@ -0,0 +1,81 @@
+From 7cb5eaeb221c322b9912f724183294d8ce96bae3 Mon Sep 17 00:00:00 2001
+From: Sutou Kouhei <kou@clear-code.com>
+Date: Sat, 17 Aug 2024 17:45:52 +0900
+Subject: [PATCH] parser tree: improve namespace conflicted attribute check 
+ performance
+
+It was slow for deep element.
+
+Reported by l33thaxor. Thanks!!!
+
+The changes to the test folder files are not included in this patch
+because the test folder was not generated during the devtool source build.
+
+CVE: CVE-2024-43398
+
+Upstream-Status: Backport [https://github.com/ruby/rexml/commit/7cb5eaeb221c322b9912f724183294d8ce96bae3]
+
+Signed-off-by: Divya Chellam <divya.chellam@windriver.com>
+---
+ .bundle/gems/rexml-3.2.5/lib/rexml/element.rb     | 11 -----------
+ .../rexml-3.2.5/lib/rexml/parsers/baseparser.rb   | 15 +++++++++++++++
+ 2 files changed, 15 insertions(+), 11 deletions(-)
+
+diff --git a/.bundle/gems/rexml-3.2.5/lib/rexml/element.rb b/.bundle/gems/rexml-3.2.5/lib/rexml/element.rb
+index 4c21dbd..78e78c2 100644
+--- a/.bundle/gems/rexml-3.2.5/lib/rexml/element.rb
++++ b/.bundle/gems/rexml-3.2.5/lib/rexml/element.rb
+@@ -2388,17 +2388,6 @@ module REXML
+       elsif old_attr.kind_of? Hash
+         old_attr[value.prefix] = value
+       elsif old_attr.prefix != value.prefix
+-        # Check for conflicting namespaces
+-        if value.prefix != "xmlns" and old_attr.prefix != "xmlns"
+-          old_namespace = old_attr.namespace
+-          new_namespace = value.namespace
+-          if old_namespace == new_namespace
+-            raise ParseException.new(
+-                    "Namespace conflict in adding attribute \"#{value.name}\": "+
+-                    "Prefix \"#{old_attr.prefix}\" = \"#{old_namespace}\" and "+
+-                    "prefix \"#{value.prefix}\" = \"#{new_namespace}\"")
+-          end
+-        end
+         store value.name, {old_attr.prefix => old_attr,
+                            value.prefix    => value}
+       else
+diff --git a/.bundle/gems/rexml-3.2.5/lib/rexml/parsers/baseparser.rb b/.bundle/gems/rexml-3.2.5/lib/rexml/parsers/baseparser.rb
+index e32c7f4..154f2ac 100644
+--- a/.bundle/gems/rexml-3.2.5/lib/rexml/parsers/baseparser.rb
++++ b/.bundle/gems/rexml-3.2.5/lib/rexml/parsers/baseparser.rb
+@@ -634,6 +634,7 @@ module REXML
+ 
+       def parse_attributes(prefixes, curr_ns)
+         attributes = {}
++        expanded_names = {}
+         closed = false
+         match_data = @source.match(/^(.*?)(\/)?>/um, true)
+         if match_data.nil?
+@@ -641,6 +642,20 @@ module REXML
+           raise REXML::ParseException.new(message, @source)
+         end
+ 
++            unless prefix == "xmlns"
++              uri = @namespaces[prefix]
++              expanded_name = [uri, local_part]
++              existing_prefix = expanded_names[expanded_name]
++              if existing_prefix
++                message = "Namespace conflict in adding attribute " +
++                          "\"#{local_part}\": " +
++                          "Prefix \"#{existing_prefix}\" = \"#{uri}\" and " +
++                          "prefix \"#{prefix}\" = \"#{uri}\""
++                raise REXML::ParseException.new(message, @source, self)
++              end
++              expanded_names[expanded_name] = prefix
++            end
++
+         raw_attributes = match_data[1]
+         closed = !match_data[2].nil?
+         return attributes, closed if raw_attributes.nil?
+-- 
+2.40.0
+
diff --git a/meta/recipes-devtools/ruby/ruby_3.1.3.bb b/meta/recipes-devtools/ruby/ruby_3.1.3.bb
index 76e5ac81ed..ca061e7f70 100644
--- a/meta/recipes-devtools/ruby/ruby_3.1.3.bb
+++ b/meta/recipes-devtools/ruby/ruby_3.1.3.bb
@@ -48,6 +48,7 @@ SRC_URI = "http://cache.ruby-lang.org/pub/ruby/${SHRT_VER}/ruby-${PV}.tar.gz \
            file://CVE-2024-41946.patch \
            file://CVE-2025-27220.patch \
            file://CVE-2025-27219.patch \
+           file://CVE-2024-43398.patch \
            "
 UPSTREAM_CHECK_URI = "https://www.ruby-lang.org/en/downloads/"