diff --git a/ruby-3.0.7-Fix-CVE-2024-27280-Buffer-overread-in-StringIO.patch b/ruby-3.0.7-Fix-CVE-2024-27280-Buffer-overread-in-StringIO.patch
new file mode 100644
index 0000000..2ad07bd
--- /dev/null
+++ b/ruby-3.0.7-Fix-CVE-2024-27280-Buffer-overread-in-StringIO.patch
@@ -0,0 +1,81 @@
+From 740289bf02c9bea54f75b702f62862c62c62672b Mon Sep 17 00:00:00 2001
+From: Hiroshi SHIBATA <hsbt@ruby-lang.org>
+Date: Thu, 21 Mar 2024 15:55:48 +0900
+Subject: [PATCH] Merge StringIO 3.0.1.1
+
+---
+ ext/stringio/stringio.c        |  2 +-
+ test/stringio/test_stringio.rb | 27 ++++++++++++++++++++++-----
+ 2 files changed, 23 insertions(+), 6 deletions(-)
+
+diff --git a/ext/stringio/stringio.c b/ext/stringio/stringio.c
+index f537054b5d..946ae06da4 100644
+--- a/ext/stringio/stringio.c
++++ b/ext/stringio/stringio.c
+@@ -833,7 +833,7 @@ strio_unget_bytes(struct StringIO *ptr, const char *cp, long cl)
+     len = RSTRING_LEN(str);
+     rest = pos - len;
+     if (cl > pos) {
+-	long ex = (rest < 0 ? cl-pos : cl+rest);
++	long ex = cl - (rest < 0 ? pos : len);
+ 	rb_str_modify_expand(str, ex);
+ 	rb_str_set_len(str, len + ex);
+ 	s = RSTRING_PTR(str);
+diff --git a/test/stringio/test_stringio.rb b/test/stringio/test_stringio.rb
+index f5169f641a..c055b901e3 100644
+--- a/test/stringio/test_stringio.rb
++++ b/test/stringio/test_stringio.rb
+@@ -693,6 +693,15 @@ def test_ungetc_padding
+     assert_equal("b""\0""a", s.string)
+   end
+ 
++  def test_ungetc_fill
++    count = 100
++    s = StringIO.new
++    s.print 'a' * count
++    s.ungetc('b' * (count * 5))
++    assert_equal((count * 5), s.string.size)
++    assert_match(/\Ab+\z/, s.string)
++  end
++
+   def test_ungetbyte_pos
+     b = '\\b00010001 \\B00010001 \\b1 \\B1 \\b000100011'
+     s = StringIO.new( b )
+@@ -718,6 +727,15 @@ def test_ungetbyte_padding
+     assert_equal("b""\0""a", s.string)
+   end
+ 
++  def test_ungetbyte_fill
++    count = 100
++    s = StringIO.new
++    s.print 'a' * count
++    s.ungetbyte('b' * (count * 5))
++    assert_equal((count * 5), s.string.size)
++    assert_match(/\Ab+\z/, s.string)
++  end
++
+   def test_frozen
+     s = StringIO.new
+     s.freeze
+@@ -760,18 +778,17 @@ def test_new_block_warning
+   end
+ 
+   def test_overflow
+-    skip if RbConfig::SIZEOF["void*"] > RbConfig::SIZEOF["long"]
++    return if RbConfig::SIZEOF["void*"] > RbConfig::SIZEOF["long"]
+     limit = (1 << (RbConfig::SIZEOF["void*"]*8-1)) - 0x10
+     assert_separately(%w[-rstringio], "#{<<-"begin;"}\n#{<<-"end;"}")
+     begin;
+       limit = #{limit}
+       ary = []
+-      while true
++      begin
+         x = "a"*0x100000
+         break if [x].pack("p").unpack("i!")[0] < 0
+         ary << x
+-        skip if ary.size > 100
+-      end
++      end while ary.size <= 100
+       s = StringIO.new(x)
+       s.gets("xxx", limit)
+       assert_equal(0x100000, s.pos)
diff --git a/ruby.spec b/ruby.spec
index 4f1a141..d2688c6 100644
--- a/ruby.spec
+++ b/ruby.spec
@@ -239,6 +239,10 @@ Patch43: ruby-3.4.0-ruby-net-http-Renew-test-certificates.patch
 # Tests not included as assert_linear_time was introduced in Ruby 2.7.
 # https://github.com/ruby/ruby/commit/616926b55e306a0704254a7ddfd6e9834d06c7f2
 Patch44: ruby-3.0.7-Fix-CVE-2023-36617-Upstreams-incomplete-fix-for-CVE-2023-28755.patch
+# CVE-2024-27280 Buffer overread vulnerability in StringIO.
+# Backported from:
+# https://github.com/ruby/ruby/commit/bd9424c71c15896a997d5a092bf5e1ed453defa6
+Patch45: ruby-3.0.7-Fix-CVE-2024-27280-Buffer-overread-in-StringIO.patch
 
 
 Requires: %{name}-libs%{?_isa} = %{version}-%{release}
@@ -654,6 +658,7 @@ sed -i 's/"evaluation\/incorrect_words.yaml"\.freeze, //' \
 %patch42 -p1
 %patch43 -p1
 %patch44 -p1
+%patch45 -p1
 
 # Provide an example of usage of the tapset:
 cp -a %{SOURCE3} .
@@ -1210,6 +1215,9 @@ OPENSSL_SYSTEM_CIPHERS_OVERRIDE=xyz_nonexistent_file OPENSSL_CONF='' \
 - Fix ReDoS vulnerability - upstream's incomplete fix for CVE-2023-28755.
   (CVE-2023-36617)
   Resolves: RHEL-5614
+- Fix Buffer overread vulnerability in StringIO.
+  (CVE-2024-27280)
+  Resolves: RHEL-34125
 
 * Mon Jun 12 2023 Jarek Prokop <jprokop@redhat.com> - 2.5.9-111
 - Fix HTTP response splitting in CGI.