diff --git a/.gitignore b/.gitignore
index 38d4126..1fbdd5c 100644
--- a/.gitignore
+++ b/.gitignore
@@ -6,6 +6,6 @@ SOURCES/nodejs-10.21.0-5.fc32.src.rpm
 SOURCES/nspr-4.25.0-1.el8_0.src.rpm
 SOURCES/nss-3.53.1-3.fc32.src.rpm
 SOURCES/openssl-1.0.2k-19.6.bundle.el7_7.src.rpm
-SOURCES/thunderbird-78.4.0.source.tar.xz
-SOURCES/thunderbird-langpacks-78.4.0-20201021.tar.xz
+SOURCES/thunderbird-78.4.3.source.tar.xz
+SOURCES/thunderbird-langpacks-78.4.3-20201112.tar.xz
 SOURCES/yasm-1.2.0-3.el5.src.rpm
diff --git a/.thunderbird.metadata b/.thunderbird.metadata
index 31d5a14..d3e1a82 100644
--- a/.thunderbird.metadata
+++ b/.thunderbird.metadata
@@ -6,6 +6,6 @@ e188ab1a444697bc649e223c28389d82ca94c472 SOURCES/libffi-3.0.13-18.el7_3.src.rpm
 07d67c90367c3ec0d6cebc1a5793c21076d34b78 SOURCES/nspr-4.25.0-1.el8_0.src.rpm
 223c02166b1cb9863b9f453ef687d7805a93e7af SOURCES/nss-3.53.1-3.fc32.src.rpm
 a379070abf5000cde61411c97af7e733b267a4d3 SOURCES/openssl-1.0.2k-19.6.bundle.el7_7.src.rpm
-66fa85ad999826bb0c53c94497a6879245f879ea SOURCES/thunderbird-78.4.0.source.tar.xz
-a7974489a76c00ff4d9386daff6b1763fc1b40db SOURCES/thunderbird-langpacks-78.4.0-20201021.tar.xz
+601516e095b3e7d16ea4f98af77859211a104d9c SOURCES/thunderbird-78.4.3.source.tar.xz
+0e97605476f032c68bb63fb7f9977f9a35567275 SOURCES/thunderbird-langpacks-78.4.3-20201112.tar.xz
 77fd30f7ebc12a629a31c1e252cec06af55a71fe SOURCES/yasm-1.2.0-3.el5.src.rpm
diff --git a/SOURCES/Bug-1238661---fix-mozillaSignalTrampoline-to-work-.patch b/SOURCES/Bug-1238661---fix-mozillaSignalTrampoline-to-work-.patch
deleted file mode 100644
index 6dfe2ad..0000000
--- a/SOURCES/Bug-1238661---fix-mozillaSignalTrampoline-to-work-.patch
+++ /dev/null
@@ -1,12 +0,0 @@
-diff -up firefox-60.0/mfbt/LinuxSignal.h.mozilla-1238661 firefox-60.0/mfbt/LinuxSignal.h
---- firefox-60.0/mfbt/LinuxSignal.h.mozilla-1238661	2018-04-27 08:55:38.848241768 +0200
-+++ firefox-60.0/mfbt/LinuxSignal.h	2018-04-27 09:06:47.946769859 +0200
-@@ -22,7 +22,7 @@ __attribute__((naked)) void SignalTrampo
-                                              void* aContext) {
-   asm volatile("nop; nop; nop; nop" : : : "memory");
- 
--  asm volatile("b %0" : : "X"(H) : "memory");
-+  asm volatile("bx %0" : : "r"(H), "l"(aSignal), "l"(aInfo), "l"(aContext) : "memory");
- }
- 
- #  define MOZ_SIGNAL_TRAMPOLINE(h) (mozilla::SignalTrampoline<h>)
diff --git a/SOURCES/Bug-1526653---fix_user_vfp_armv7.patch b/SOURCES/Bug-1526653---fix_user_vfp_armv7.patch
deleted file mode 100644
index 3f84f95..0000000
--- a/SOURCES/Bug-1526653---fix_user_vfp_armv7.patch
+++ /dev/null
@@ -1,35 +0,0 @@
-From fd6847c9416f9eebde636e21d794d25d1be8791d Mon Sep 17 00:00:00 2001
-From: Mike Hommey <mh@glandium.org>
-Date: Sat, 1 Jun 2019 09:06:01 +0900
-Subject: [PATCH] Bug 1526653 - Include struct definitions for user_vfp and
- user_vfp_exc.
-
----
- js/src/wasm/WasmSignalHandlers.cpp | 11 ++++++++++-
- 1 file changed, 10 insertions(+), 1 deletion(-)
-
-diff --git a/js/src/wasm/WasmSignalHandlers.cpp b/js/src/wasm/WasmSignalHandlers.cpp
-index 636537f8478..383c380f04c 100644
---- a/js/src/wasm/WasmSignalHandlers.cpp
-+++ b/js/src/wasm/WasmSignalHandlers.cpp
-@@ -248,7 +248,16 @@ using mozilla::DebugOnly;
- #endif
- 
- #ifdef WASM_EMULATE_ARM_UNALIGNED_FP_ACCESS
--#  include <sys/user.h>
-+struct user_vfp {
-+  unsigned long long fpregs[32];
-+  unsigned long fpscr;
-+};
-+
-+struct user_vfp_exc {
-+  unsigned long fpexc;
-+  unsigned long fpinst;
-+  unsigned long fpinst2;
-+};
- #endif
- 
- #if defined(ANDROID)
--- 
-2.20.1
-
diff --git a/SOURCES/rhel6-at-no-automount.patch b/SOURCES/rhel6-at-no-automount.patch
new file mode 100644
index 0000000..830ed54
--- /dev/null
+++ b/SOURCES/rhel6-at-no-automount.patch
@@ -0,0 +1,27 @@
+diff -ru firefox-78.3.0/security/sandbox/linux/SandboxFilter.cpp firefox-78.4.0/security/sandbox/linux/SandboxFilter.cpp
+--- firefox-78.3.0/security/sandbox/linux/SandboxFilter.cpp	2020-09-14 21:21:02.000000000 +0200
++++ firefox-78.4.0/security/sandbox/linux/SandboxFilter.cpp	2020-10-14 11:34:48.000000000 +0200
+@@ -243,14 +243,21 @@
+     auto path = reinterpret_cast<const char*>(aArgs.args[1]);
+     auto buf = reinterpret_cast<statstruct*>(aArgs.args[2]);
+     auto flags = static_cast<int>(aArgs.args[3]);
++
++    if (fd != AT_FDCWD && (flags & AT_EMPTY_PATH) != 0 &&
++        strcmp(path, "") == 0) {
++      return ConvertError(fstatsyscall(fd, buf));
++    }
++
+     if (fd != AT_FDCWD && path[0] != '/') {
+       SANDBOX_LOG_ERROR("unsupported fd-relative fstatat(%d, \"%s\", %p, %d)",
+                         fd, path, buf, flags);
+       return BlockedSyscallTrap(aArgs, nullptr);
+     }
+-    if ((flags & ~AT_SYMLINK_NOFOLLOW) != 0) {
++    if ((flags & ~(AT_SYMLINK_NOFOLLOW | AT_NO_AUTOMOUNT)) != 0) {
+       SANDBOX_LOG_ERROR("unsupported flags %d in fstatat(%d, \"%s\", %p, %d)",
+-                        (flags & ~AT_SYMLINK_NOFOLLOW), fd, path, buf, flags);
++                        (flags & ~(AT_SYMLINK_NOFOLLOW | AT_NO_AUTOMOUNT)), fd,
++                        path, buf, flags);
+       return BlockedSyscallTrap(aArgs, nullptr);
+     }
+     return (flags & AT_SYMLINK_NOFOLLOW) == 0 ? broker->Stat(path, buf)
diff --git a/SOURCES/rhel6-clock_gettime.patch b/SOURCES/rhel6-clock_gettime.patch
new file mode 100644
index 0000000..d33f1a6
--- /dev/null
+++ b/SOURCES/rhel6-clock_gettime.patch
@@ -0,0 +1,12 @@
+diff -up thunderbird-78.3.1/comm/third_party/botan/src/lib/utils/os_utils.cpp.rhel6-clock_gettime thunderbird-78.3.1/comm/third_party/botan/src/lib/utils/os_utils.cpp
+--- thunderbird-78.3.1/comm/third_party/botan/src/lib/utils/os_utils.cpp.rhel6-clock_gettime	2020-09-29 21:41:52.180409804 +0200
++++ thunderbird-78.3.1/comm/third_party/botan/src/lib/utils/os_utils.cpp	2020-09-29 21:42:54.438565760 +0200
+@@ -254,6 +254,8 @@ uint64_t OS::get_high_resolution_clock()
+    fall back to std::chrono.
+    */
+ 
++#undef BOTAN_TARGET_OS_HAS_CLOCK_GETTIME
++
+ #if defined(BOTAN_TARGET_OS_HAS_CLOCK_GETTIME)
+ 
+    // The ordering here is somewhat arbitrary...
diff --git a/SOURCES/thunderbird-centos-default-prefs.js.el6 b/SOURCES/thunderbird-centos-default-prefs.js.el6
deleted file mode 100644
index a277f3d..0000000
--- a/SOURCES/thunderbird-centos-default-prefs.js.el6
+++ /dev/null
@@ -1,33 +0,0 @@
-pref("app.update.enabled", false);
-pref("app.update.autoInstallEnabled", false);
-# Allow users to set custom colors
-# pref("browser.display.use_system_colors",   true);
-pref("general.useragent.vendor", "CentOS");
-pref("general.useragent.vendorSub", "THUNDERBIRD_RPM_VR");
-pref("intl.locale.matchOS", true);
-pref("mail.shell.checkDefaultClient", false);
-pref("toolkit.networkmanager.disable", false);
-pref("offline.autoDetect", true);
-
-# Disable global indexing by default
-pref("mailnews.database.global.indexer.enabled", false);
-
-# Do not switch to Smart Folders after upgrade to 3.0b4
-pref("mail.folder.views.version", "1");
-pref("extensions.shownSelectionUI", true);
-pref("extensions.autoDisableScope", 0);
-
-# For rhbz#1024232
-pref("ui.SpellCheckerUnderlineStyle",       1);
-
-/* Workaround for rhbz#1134876 */
-pref("javascript.options.baselinejit",      false);
-/* Workaround for rhbz#1110291 */
-pref("network.negotiate-auth.allow-insecure-ntlm-v1", true);
-/* Workaround for mozbz#1063315 */
-pref("security.use_mozillapkix_verification", false);
-/* Use OS settings for UI language */
-pref("intl.locale.requested", "");
-pref("datareporting.healthreport.uploadEnabled", false);
-pref("datareporting.policy.dataSubmissionEnabled", false);
-pref("toolkit.telemetry.archive.enabled", false);
diff --git a/SOURCES/thunderbird-centos-default-prefs.js.el7 b/SOURCES/thunderbird-centos-default-prefs.js.el7
deleted file mode 100644
index a277f3d..0000000
--- a/SOURCES/thunderbird-centos-default-prefs.js.el7
+++ /dev/null
@@ -1,33 +0,0 @@
-pref("app.update.enabled", false);
-pref("app.update.autoInstallEnabled", false);
-# Allow users to set custom colors
-# pref("browser.display.use_system_colors",   true);
-pref("general.useragent.vendor", "CentOS");
-pref("general.useragent.vendorSub", "THUNDERBIRD_RPM_VR");
-pref("intl.locale.matchOS", true);
-pref("mail.shell.checkDefaultClient", false);
-pref("toolkit.networkmanager.disable", false);
-pref("offline.autoDetect", true);
-
-# Disable global indexing by default
-pref("mailnews.database.global.indexer.enabled", false);
-
-# Do not switch to Smart Folders after upgrade to 3.0b4
-pref("mail.folder.views.version", "1");
-pref("extensions.shownSelectionUI", true);
-pref("extensions.autoDisableScope", 0);
-
-# For rhbz#1024232
-pref("ui.SpellCheckerUnderlineStyle",       1);
-
-/* Workaround for rhbz#1134876 */
-pref("javascript.options.baselinejit",      false);
-/* Workaround for rhbz#1110291 */
-pref("network.negotiate-auth.allow-insecure-ntlm-v1", true);
-/* Workaround for mozbz#1063315 */
-pref("security.use_mozillapkix_verification", false);
-/* Use OS settings for UI language */
-pref("intl.locale.requested", "");
-pref("datareporting.healthreport.uploadEnabled", false);
-pref("datareporting.policy.dataSubmissionEnabled", false);
-pref("toolkit.telemetry.archive.enabled", false);
diff --git a/SOURCES/thunderbird-redhat-default-prefs.js.rhel6 b/SOURCES/thunderbird-redhat-default-prefs.js.rhel6
new file mode 100644
index 0000000..26e8d17
--- /dev/null
+++ b/SOURCES/thunderbird-redhat-default-prefs.js.rhel6
@@ -0,0 +1,33 @@
+pref("app.update.enabled", false);
+pref("app.update.autoInstallEnabled", false);
+# Allow users to set custom colors
+# pref("browser.display.use_system_colors",   true);
+pref("general.useragent.vendor", "Red Hat");
+pref("general.useragent.vendorSub", "THUNDERBIRD_RPM_VR");
+pref("intl.locale.matchOS", true);
+pref("mail.shell.checkDefaultClient", false);
+pref("toolkit.networkmanager.disable", false);
+pref("offline.autoDetect", true);
+
+# Disable global indexing by default
+pref("mailnews.database.global.indexer.enabled", false);
+
+# Do not switch to Smart Folders after upgrade to 3.0b4
+pref("mail.folder.views.version", "1");
+pref("extensions.shownSelectionUI", true);
+pref("extensions.autoDisableScope", 0);
+
+# For rhbz#1024232
+pref("ui.SpellCheckerUnderlineStyle",       1);
+
+/* Workaround for rhbz#1134876 */
+pref("javascript.options.baselinejit",      false);
+/* Workaround for rhbz#1110291 */
+pref("network.negotiate-auth.allow-insecure-ntlm-v1", true);
+/* Workaround for mozbz#1063315 */
+pref("security.use_mozillapkix_verification", false);
+/* Use OS settings for UI language */
+pref("intl.locale.requested", "");
+pref("datareporting.healthreport.uploadEnabled", false);
+pref("datareporting.policy.dataSubmissionEnabled", false);
+pref("toolkit.telemetry.archive.enabled", false);
diff --git a/SOURCES/thunderbird-redhat-default-prefs.js.rhel7 b/SOURCES/thunderbird-redhat-default-prefs.js.rhel7
new file mode 100644
index 0000000..26e8d17
--- /dev/null
+++ b/SOURCES/thunderbird-redhat-default-prefs.js.rhel7
@@ -0,0 +1,33 @@
+pref("app.update.enabled", false);
+pref("app.update.autoInstallEnabled", false);
+# Allow users to set custom colors
+# pref("browser.display.use_system_colors",   true);
+pref("general.useragent.vendor", "Red Hat");
+pref("general.useragent.vendorSub", "THUNDERBIRD_RPM_VR");
+pref("intl.locale.matchOS", true);
+pref("mail.shell.checkDefaultClient", false);
+pref("toolkit.networkmanager.disable", false);
+pref("offline.autoDetect", true);
+
+# Disable global indexing by default
+pref("mailnews.database.global.indexer.enabled", false);
+
+# Do not switch to Smart Folders after upgrade to 3.0b4
+pref("mail.folder.views.version", "1");
+pref("extensions.shownSelectionUI", true);
+pref("extensions.autoDisableScope", 0);
+
+# For rhbz#1024232
+pref("ui.SpellCheckerUnderlineStyle",       1);
+
+/* Workaround for rhbz#1134876 */
+pref("javascript.options.baselinejit",      false);
+/* Workaround for rhbz#1110291 */
+pref("network.negotiate-auth.allow-insecure-ntlm-v1", true);
+/* Workaround for mozbz#1063315 */
+pref("security.use_mozillapkix_verification", false);
+/* Use OS settings for UI language */
+pref("intl.locale.requested", "");
+pref("datareporting.healthreport.uploadEnabled", false);
+pref("datareporting.policy.dataSubmissionEnabled", false);
+pref("toolkit.telemetry.archive.enabled", false);
diff --git a/SPECS/thunderbird.spec b/SPECS/thunderbird.spec
index c59e6c7..aa2f672 100644
--- a/SPECS/thunderbird.spec
+++ b/SPECS/thunderbird.spec
@@ -1,7 +1,3 @@
-%ifarch %{arm}
-%undefine _debugsource_packages
-%endif
-
 # Set for local builds only
 %global disable_toolsets  0
 
@@ -195,7 +191,7 @@
 %global build_langpacks         1
 Summary:        Mozilla Thunderbird mail/newsgroup client
 Name:           thunderbird
-Version:        78.4.0
+Version:        78.4.3
 Release:        1%{?dist}
 URL:            http://www.mozilla.org/projects/thunderbird/
 License:        MPLv1.1 or GPLv2+ or LGPLv2+
@@ -211,7 +207,7 @@ ExclusiveArch:  i686 x86_64 ppc64 s390x
 # From ftp://archive.mozilla.org/pub/thunderbird/releases/%{version}%{?ext_version}/source
 Source0:        https://archive.mozilla.org/pub/thunderbird/releases/%{version}%{?pre_version}/source/thunderbird-%{version}%{?pre_version}.source.tar.xz
 %if %{build_langpacks}
-Source1:        thunderbird-langpacks-%{version}%{?ext_version}-20201021.tar.xz
+Source1:        thunderbird-langpacks-%{version}%{?ext_version}-20201112.tar.xz
 # Locales for lightning
 %endif
 Source2:        cbindgen-vendor-0.14.3.tar.xz
@@ -235,8 +231,8 @@ Source301:      yasm-1.2.0-3.el5.src.rpm
 Source303:      libffi-3.0.13-18.el7_3.src.rpm
 Source304:      nodejs-10.21.0-5.fc32.src.rpm
 Source305:      openssl-1.0.2k-19.6.bundle.el7_7.src.rpm
-Source601:      thunderbird-centos-default-prefs.js.el6
-Source701:      thunderbird-centos-default-prefs.js.el7
+Source601:      thunderbird-redhat-default-prefs.js.rhel6
+Source701:      thunderbird-redhat-default-prefs.js.rhel7
 
 ## Firefox patches
 
@@ -307,6 +303,8 @@ Patch603:        rhel6-zconst.patch
 Patch604:        rhel6-auxvh.patch
 Patch605:        rhel6-abiv2-mozbz1642174.patch
 Patch606:        rhel6-auxv.patch
+Patch607:        rhel6-at-no-automount.patch
+Patch608:        rhel6-clock_gettime.patch
 
 %if %{?system_nss}
 %if !0%{?bundle_nss}
@@ -611,6 +609,8 @@ echo "use_bundled_yasm      %{?use_bundled_yasm}"
 %patch604 -p1 -b .rhel6-auxvh
 %patch605 -p1 -b .rhel6-abiv2-mozbz1642174
 %patch606 -p1 -b .rhel6-auxv
+%patch607 -p1 -R -b .rhel6-at-no-automount
+%patch608 -p1 -b .rhel6-clock_gettime
 %endif
 
 # CentOS patches
@@ -669,7 +669,7 @@ echo "ac_add_options --enable-system-hunspell" >> .mozconfig
 %endif
 %ifarch armv7hl
 # ARMv7 need that (rhbz#1426850)
-%global optimize_flags "-g0 -O2 -fno-schedule-insns -fno-lto"
+%global optimize_flags "-g -O2 -fno-schedule-insns"
 %endif
 %ifarch ppc64le aarch64
 %global optimize_flags "-g -O2"
@@ -876,7 +876,19 @@ function build_bundled_package() {
   %filter_from_requires /libssl3.so.*/d
   %filter_from_requires /libnssutil3.so.*/d
   %filter_from_requires /libnspr4.so.*/d
+%endif
 
+%if 0%{?rhel} == 6
+  %filter_from_requires /libnss3.so.*/d
+  %filter_from_requires /libsmime3.so.*/d
+  %filter_from_requires /libssl3.so.*/d
+  %filter_from_requires /libnssutil3.so.*/d
+  %filter_from_requires /libnspr4.so.*/d
+  %filter_from_provides /libnss3.so.*/d
+  %filter_from_provides /libsmime3.so.*/d
+  %filter_from_provides /libssl3.so.*/d
+  %filter_from_provides /libnssutil3.so.*/d
+  %filter_from_provides /libnspr4.so.*/d
 %endif
 
 %if 0%{?bundle_gtk3}
@@ -1049,10 +1061,6 @@ MOZ_OPT_FLAGS=$(echo "$MOZ_OPT_FLAGS" | %{__sed} -e 's/-g/-g1/')
 # (OOM when linking, rhbz#1238225)
 export MOZ_DEBUG_FLAGS=" "
 %endif
-%ifarch %{arm}
-MOZ_OPT_FLAGS=$(echo "$MOZ_OPT_FLAGS" | %{__sed} -e 's/-g/-g0/')
-export MOZ_DEBUG_FLAGS=" "
-%endif
 
 # We don't wantfirefox to use CK_GCM_PARAMS_V3 in nss
 MOZ_OPT_FLAGS="$MOZ_OPT_FLAGS -DNSS_PKCS11_3_0_STRICT"
@@ -1430,8 +1438,8 @@ gtk-update-icon-cache %{_datadir}/icons/hicolor &>/dev/null || :
 #===============================================================================
 
 %changelog
-* Wed Nov 04 2020 CentOS Sources <bugs@centos.org> - 78.4.0-1.el8.centos
-- Apply debranding changes
+* Thu Nov 12 2020 Eike Rathke <erack@redhat.com> - 78.4.3-1
+- Update to 78.4.3
 
 * Wed Oct 21 2020 Eike Rathke <erack@redhat.com> - 78.4.0-1
 - Update to 78.4.0 build1