diff --git a/lz4-cve-2021-3520.patch b/lz4-cve-2021-3520.patch
new file mode 100644
index 0000000..8a22dce
--- /dev/null
+++ b/lz4-cve-2021-3520.patch
@@ -0,0 +1,22 @@
+From 8301a21773ef61656225e264f4f06ae14462bca7 Mon Sep 17 00:00:00 2001
+From: Jasper Lievisse Adriaanse <j@jasper.la>
+Date: Fri, 26 Feb 2021 15:21:20 +0100
+Subject: [PATCH] Fix potential memory corruption with negative memmove() size
+
+---
+ lib/lz4.c | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+diff --git a/lib/lz4.c b/lib/lz4.c
+index 5f524d01..c2f504ef 100644
+--- a/lib/lz4.c
++++ b/lib/lz4.c
+@@ -1749,7 +1749,7 @@ LZ4_decompress_generic(
+                  const size_t dictSize         /* note : = 0 if noDict */
+                  )
+ {
+-    if (src == NULL) { return -1; }
++    if ((src == NULL) || (outputSize < 0)) { return -1; }
+ 
+     {   const BYTE* ip = (const BYTE*) src;
+         const BYTE* const iend = ip + srcSize;
diff --git a/lz4.spec b/lz4.spec
index cad40f6..2085683 100644
--- a/lz4.spec
+++ b/lz4.spec
@@ -2,7 +2,7 @@
 
 Name:           lz4
 Version:        1.9.3
-Release:        3%{?dist}
+Release:        4%{?dist}
 Summary:        Extremely fast compression algorithm
 
 License:        GPLv2+ and BSD
@@ -15,6 +15,7 @@ BuildRequires: make
 BuildRequires:  gcc
 BuildRequires:  meson >= 0.43
 
+Patch1: lz4-cve-2021-3520.patch
 %description
 LZ4 is an extremely fast loss-less compression algorithm, providing compression
 speed at 400 MB/s per core, scalable with multi-core CPU. It also features
@@ -44,7 +45,7 @@ LZ4 is an extremely fast loss-less compression algorithm. This package
 contains static libraries for static linking of applications.
 
 %prep
-%autosetup
+%autosetup -p1
 
 %build
 %meson \
@@ -82,6 +83,10 @@ contains static libraries for static linking of applications.
 %{_libdir}/liblz4.a
 
 %changelog
+* Thu May 27 2021 Jakub Martisko <jamartis@redhat.com> - 1.9.3-4
+- Fix cve-2021-3520
+resolves: cve-2021-3520
+
 * Fri Apr 16 2021 Mohan Boddu <mboddu@redhat.com> - 1.9.3-3
 - Rebuilt for RHEL 9 BETA on Apr 15th 2021. Related: rhbz#1947937