diff --git a/CVE-2023-36328.patch b/CVE-2023-36328.patch
new file mode 100644
index 0000000..00f2215
--- /dev/null
+++ b/CVE-2023-36328.patch
@@ -0,0 +1,106 @@
+From beba892bc0d4e4ded4d667ab1d2a94f4d75109a9 Mon Sep 17 00:00:00 2001
+From: czurnieden <czurnieden@gmx.de>
+Date: Tue, 9 May 2023 17:17:12 +0200
+Subject: [PATCH] Fix possible integer overflow
+
+[fsumsal] Slightly altered to make it work with libtommath-1.1.0
+
+---
+ bn_mp_2expt.c                | 4 ++++
+ bn_mp_grow.c                 | 4 ++++
+ bn_mp_init_size.c            | 5 +++++
+ bn_mp_mul_2d.c               | 4 ++++
+ bn_s_mp_mul_digs.c           | 4 ++++
+ bn_s_mp_mul_high_digs.c      | 4 ++++
+ 8 files changed, 33 insertions(+)
+
+diff --git a/bn_mp_2expt.c b/bn_mp_2expt.c
+index 0ae3df1bf..23de0c3c5 100644
+--- a/bn_mp_2expt.c
++++ b/bn_mp_2expt.c
+@@ -12,6 +12,10 @@ mp_err mp_2expt(mp_int *a, int b)
+ {
+    int     res;
+ 
++   if (b < 0) {
++      return MP_VAL;
++   }
++
+    /* zero a as per default */
+    mp_zero(a);
+ 
+diff --git a/bn_mp_grow.c b/bn_mp_grow.c
+index 9e904c547..2b1682651 100644
+--- a/bn_mp_grow.c
++++ b/bn_mp_grow.c
+@@ -9,6 +9,10 @@ mp_err mp_grow(mp_int *a, int size)
+    int     i;
+    mp_digit *tmp;
+ 
++   if (size < 0) {
++      return MP_VAL;
++   }
++
+    /* if the alloc size is smaller alloc more ram */
+    if (a->alloc < size) {
+       /* ensure there are always at least MP_PREC digits extra on top */
+diff --git a/bn_mp_init_size.c b/bn_mp_init_size.c
+index d62268721..99573833f 100644
+--- a/bn_mp_init_size.c
++++ b/bn_mp_init_size.c
+@@ -6,6 +6,10 @@
+ {
+    int x;
+ 
++   if (size < 0) {
++      return MP_VAL;
++   }
++
+    /* pad size so there are always extra digits */
+    size += (MP_PREC * 2) - (size % MP_PREC);
+ 
+diff --git a/bn_mp_mul_2d.c b/bn_mp_mul_2d.c
+index 87354de20..bfeaf2eb2 100644
+--- a/bn_mp_mul_2d.c
++++ b/bn_mp_mul_2d.c
+@@ -9,6 +9,10 @@ mp_err mp_mul_2d(const mp_int *a, int b, mp_int *c)
+    mp_digit d;
+    int      res;
+ 
++   if (b < 0) {
++      return MP_VAL;
++   }
++
+    /* copy */
+    if (a != c) {
+       if ((res = mp_copy(a, c)) != MP_OKAY) {
+diff --git a/bn_s_mp_mul_digs.c b/bn_s_mp_mul_digs.c
+index 64509d4cb..3682b4980 100644
+--- a/bn_s_mp_mul_digs.c
++++ b/bn_s_mp_mul_digs.c
+@@ -16,6 +16,10 @@ mp_err s_mp_mul_digs(const mp_int *a, const mp_int *b, mp_int *c, int digs)
+    mp_word r;
+    mp_digit tmpx, *tmpt, *tmpy;
+ 
++   if (digs < 0) {
++      return MP_VAL;
++   }
++
+    /* can we use the fast multiplier? */
+    if ((digs < (int)MP_WARRAY) &&
+        (MIN(a->used, b->used) <
+diff --git a/bn_s_mp_mul_high_digs.c b/bn_s_mp_mul_high_digs.c
+index 2bb2a5098..c9dd355f8 100644
+--- a/bn_s_mp_mul_high_digs.c
++++ b/bn_s_mp_mul_high_digs.c
+@@ -15,6 +15,10 @@ mp_err s_mp_mul_high_digs(const mp_int *a, const mp_int *b, mp_int *c, int digs)
+    mp_word r;
+    mp_digit tmpx, *tmpt, *tmpy;
+ 
++   if (digs < 0) {
++      return MP_VAL;
++   }
++
+    /* can we use the fast multiplier? */
+ #ifdef BN_FAST_S_MP_MUL_HIGH_DIGS_C
+    if (((a->used + b->used + 1) < (int)MP_WARRAY)
diff --git a/libtommath.spec b/libtommath.spec
index 67580b0..a09f060 100644
--- a/libtommath.spec
+++ b/libtommath.spec
@@ -7,6 +7,8 @@ URL:            http://www.libtom.net/
 
 Source0:        https://github.com/libtom/%{name}/archive/v%{version}.tar.gz#/%{name}-%{version}.tar.gz
 
+Patch:          CVE-2023-36328.patch
+
 BuildRequires:  ghostscript
 BuildRequires:  libtiff-tools
 BuildRequires:  libtool
@@ -44,7 +46,7 @@ Obsoletes:      %{name}-doc < 0.42-1
 The %{name}-doc package contains PDF documentation for using %{name}.
 
 %prep
-%setup -q
+%autosetup -p1
 # Fix permissions on installed library
 sed -i -e 's/644 $(LIBNAME)/755 $(LIBNAME)/g' makefile.shared
 # Fix pkgconfig path