diff --git a/SOURCES/0006-Fix-ALPACA-security-issue.patch b/SOURCES/0006-Fix-ALPACA-security-issue.patch
new file mode 100644
index 0000000..754e8cc
--- /dev/null
+++ b/SOURCES/0006-Fix-ALPACA-security-issue.patch
@@ -0,0 +1,96 @@
+From ee8ea4f1c88a0393206769cd30a545dc3375f868 Mon Sep 17 00:00:00 2001
+From: =?UTF-8?q?Lubo=C5=A1=20Uhliarik?= <luhliari@redhat.com>
+Date: Wed, 2 Feb 2022 20:14:55 +0100
+Subject: [PATCH] Fix ALPACA security issue
+
+---
+ src/mail/ngx_mail.h             |  3 +++
+ src/mail/ngx_mail_core_module.c | 10 ++++++++++
+ src/mail/ngx_mail_handler.c     | 15 ++++++++++++++-
+ 3 files changed, 27 insertions(+), 1 deletion(-)
+
+diff --git a/src/mail/ngx_mail.h b/src/mail/ngx_mail.h
+index b865a3b..76cae37 100644
+--- a/src/mail/ngx_mail.h
++++ b/src/mail/ngx_mail.h
+@@ -115,6 +115,8 @@ typedef struct {
+     ngx_msec_t              timeout;
+     ngx_msec_t              resolver_timeout;
+ 
++    ngx_uint_t              max_errors;
++
+     ngx_str_t               server_name;
+ 
+     u_char                 *file_name;
+@@ -231,6 +233,7 @@ typedef struct {
+     ngx_uint_t              command;
+     ngx_array_t             args;
+ 
++    ngx_uint_t              errors;
+     ngx_uint_t              login_attempt;
+ 
+     /* used to parse POP3/IMAP/SMTP command */
+diff --git a/src/mail/ngx_mail_core_module.c b/src/mail/ngx_mail_core_module.c
+index 4083124..115671c 100644
+--- a/src/mail/ngx_mail_core_module.c
++++ b/src/mail/ngx_mail_core_module.c
+@@ -85,6 +85,13 @@ static ngx_command_t  ngx_mail_core_commands[] = {
+       offsetof(ngx_mail_core_srv_conf_t, resolver_timeout),
+       NULL },
+ 
++    { ngx_string("max_errors"),
++      NGX_MAIL_MAIN_CONF|NGX_MAIL_SRV_CONF|NGX_CONF_TAKE1,
++      ngx_conf_set_num_slot,
++      NGX_MAIL_SRV_CONF_OFFSET,
++      offsetof(ngx_mail_core_srv_conf_t, max_errors),
++      NULL },
++
+       ngx_null_command
+ };
+ 
+@@ -163,6 +170,8 @@ ngx_mail_core_create_srv_conf(ngx_conf_t *cf)
+     cscf->timeout = NGX_CONF_UNSET_MSEC;
+     cscf->resolver_timeout = NGX_CONF_UNSET_MSEC;
+ 
++    cscf->max_errors = NGX_CONF_UNSET_UINT;
++
+     cscf->resolver = NGX_CONF_UNSET_PTR;
+ 
+     cscf->file_name = cf->conf_file->file.name.data;
+@@ -182,6 +191,7 @@ ngx_mail_core_merge_srv_conf(ngx_conf_t *cf, void *parent, void *child)
+     ngx_conf_merge_msec_value(conf->resolver_timeout, prev->resolver_timeout,
+                               30000);
+ 
++    ngx_conf_merge_uint_value(conf->max_errors, prev->max_errors, 5);
+ 
+     ngx_conf_merge_str_value(conf->server_name, prev->server_name, "");
+ 
+diff --git a/src/mail/ngx_mail_handler.c b/src/mail/ngx_mail_handler.c
+index 0aaa0e7..71b8151 100644
+--- a/src/mail/ngx_mail_handler.c
++++ b/src/mail/ngx_mail_handler.c
+@@ -871,7 +871,20 @@ ngx_mail_read_command(ngx_mail_session_t *s, ngx_connection_t *c)
+         return NGX_MAIL_PARSE_INVALID_COMMAND;
+     }
+ 
+-    if (rc == NGX_IMAP_NEXT || rc == NGX_MAIL_PARSE_INVALID_COMMAND) {
++    if (rc == NGX_MAIL_PARSE_INVALID_COMMAND) {
++
++        s->errors++;
++
++        if (s->errors >= cscf->max_errors) {
++            ngx_log_error(NGX_LOG_INFO, c->log, 0,
++                          "client sent too many invalid commands");
++            s->quit = 1;
++        }
++
++        return rc;
++    }
++
++    if (rc == NGX_IMAP_NEXT) {
+         return rc;
+     }
+ 
+-- 
+2.31.1
+
diff --git a/SPECS/nginx.spec b/SPECS/nginx.spec
index 0d369a0..a9093bd 100644
--- a/SPECS/nginx.spec
+++ b/SPECS/nginx.spec
@@ -41,7 +41,7 @@
 Name:              nginx
 Epoch:             1
 Version:           1.20.1
-Release:           9%{?dist}
+Release:           10%{?dist}
 
 Summary:           A high performance web server and reverse proxy server
 # BSD License (two clause)
@@ -85,6 +85,9 @@ Patch3:            0004-Set-proper-compiler-optimalization-level-O2-for-perl.pat
 # downstream patch for RHEL - https://bugzilla.redhat.com/show_bug.cgi?id=2006420
 Patch4:            0005-Init-openssl-engine-properly.patch
 
+# upstream patch - fixing ALPACA(CVE-2021-3618) security issue - https://bugzilla.redhat.com/show_bug.cgi?id=1975623
+Patch5:            0006-Fix-ALPACA-security-issue.patch
+
 BuildRequires:     make
 BuildRequires:     gcc
 BuildRequires:     gnupg2
@@ -584,6 +587,10 @@ fi
 
 
 %changelog
+* Wed Feb 02 2022 Luboš Uhliarik <luhliari@redhat.com> - 1:1.20.1-10
+- Resolves: #1975747 - CVE-2021-3618 nginx: ALPACA: Application Layer Protocol
+  Confusion - Analyzing and Mitigating Cracks in TLS Authentication
+
 * Thu Dec  2 2021 Joe Orton <jorton@redhat.com> - 1:1.20.1-9
 - add delaycompress to logrotate config (#2015250)