diff --git a/cve-2021-43618.patch b/cve-2021-43618.patch
new file mode 100644
index 0000000..f741972
--- /dev/null
+++ b/cve-2021-43618.patch
@@ -0,0 +1,25 @@
+
+# HG changeset patch
+# User Marco Bodrato <bodrato@mail.dm.unipi.it>
+# Date 1634836009 -7200
+# Node ID 561a9c25298e17bb01896801ff353546c6923dbd
+# Parent  e1fd9db13b475209a864577237ea4b9105b3e96e
+mpz/inp_raw.c: Avoid bit size overflows
+
+diff -r e1fd9db13b47 -r 561a9c25298e mpz/inp_raw.c
+--- a/mpz/inp_raw.c	Tue Dec 22 23:49:51 2020 +0100
++++ b/mpz/inp_raw.c	Thu Oct 21 19:06:49 2021 +0200
+@@ -88,8 +88,11 @@
+ 
+   abs_csize = ABS (csize);
+ 
++  if (UNLIKELY (abs_csize > ~(mp_bitcnt_t) 0 / 8))
++    return 0; /* Bit size overflows */
++
+   /* round up to a multiple of limbs */
+-  abs_xsize = BITS_TO_LIMBS (abs_csize*8);
++  abs_xsize = BITS_TO_LIMBS ((mp_bitcnt_t) abs_csize * 8);
+ 
+   if (abs_xsize != 0)
+     {
+
diff --git a/gmp.spec b/gmp.spec
index ef13a76..431f061 100644
--- a/gmp.spec
+++ b/gmp.spec
@@ -15,6 +15,7 @@ Source2: gmp.h
 Source3: gmp-mparam.h
 Patch2: gmp-6.0.0-debuginfo.patch
 Patch3: gmp-fcf-protection.patch
+Patch4: cve-2021-43618.patch
 License: LGPLv3+ or GPLv2+
 Group: System Environment/Libraries
 BuildRoot: %{_tmppath}/%{name}-%{version}-%{release}-root-%(%{__id_u} -n)
@@ -200,6 +201,10 @@ exit 0
 %{_libdir}/libgmpxx.a
 
 %changelog
+* Mon Jan 29 2024 Jakub Martisko <jamartis@redhat.com> - 1:6.1.2-11
+- Fix: CVE-2021-43618
+Resolves: CVE-2021-43618
+
 * Fri Jun 14 2019 Jakub Martisko <jamartis@redhat.com> - 1:6.1.2-10
 - Add gating.yaml
 Related: #1681026