diff --git a/MozillaThunderbird.changes b/MozillaThunderbird.changes
index b30d188..d0c6870 100644
--- a/MozillaThunderbird.changes
+++ b/MozillaThunderbird.changes
@@ -1,3 +1,11 @@
+-------------------------------------------------------------------
+Tue Dec  1 21:34:15 UTC 2020 - Wolfgang Rosenauer <wr@rosenauer.org>
+
+- Mozilla Thunderbird 78.5.1
+  MFSA 2020-53 (bsc#1179530)
+  * CVE-2020-26970 (bmo#1677338)
+    Stack overflow due to incorrect parsing of SMTP server response codes
+
 -------------------------------------------------------------------
 Mon Nov 16 20:13:34 UTC 2020 - Wolfgang Rosenauer <wr@rosenauer.org>
 
diff --git a/MozillaThunderbird.spec b/MozillaThunderbird.spec
index 534f526..0523d14 100644
--- a/MozillaThunderbird.spec
+++ b/MozillaThunderbird.spec
@@ -26,8 +26,8 @@
 # major 69
 # mainver %major.99
 %define major          78
-%define mainver        %major.5.0
-%define orig_version   78.5.0
+%define mainver        %major.5.1
+%define orig_version   78.5.1
 %define orig_suffix    %{nil}
 %define update_channel release
 %define source_prefix  thunderbird-%{orig_version}
diff --git a/l10n-78.5.0.tar.xz b/l10n-78.5.0.tar.xz
deleted file mode 100644
index af3c61b..0000000
--- a/l10n-78.5.0.tar.xz
+++ /dev/null
@@ -1,3 +0,0 @@
-version https://git-lfs.github.com/spec/v1
-oid sha256:ef3558575e0029648e28a23b8b57baccf7e53df1aec39bd316d21fe39317eee9
-size 29083668
diff --git a/l10n-78.5.1.tar.xz b/l10n-78.5.1.tar.xz
new file mode 100644
index 0000000..c5a5af4
--- /dev/null
+++ b/l10n-78.5.1.tar.xz
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:70a191f497133377e1a2d890f6d9742046f44ae36475686fd7d1e1e867c73016
+size 29083288
diff --git a/tar_stamps b/tar_stamps
index 7f748e2..85f2759 100644
--- a/tar_stamps
+++ b/tar_stamps
@@ -1,10 +1,10 @@
 PRODUCT="thunderbird"
 CHANNEL="esr78"
-VERSION="78.5.0"
+VERSION="78.5.1"
 VERSION_SUFFIX=""
-PREV_VERSION="78.4.3"
+PREV_VERSION="78.5.0"
 PREV_VERSION_SUFFIX=""
 #SKIP_LOCALES="" # Uncomment to skip l10n and compare-locales-generation
 RELEASE_REPO="https://hg.mozilla.org/releases/comm-esr78"
-RELEASE_TAG="92abc26b9c80383e974fb0234f22e06fea793be2"
-RELEASE_TIMESTAMP="20201116161136"
+RELEASE_TAG="7bfb6e5797a4120c798eaa67a9cddd2846badcee"
+RELEASE_TIMESTAMP="20201130232704"
diff --git a/thunderbird-78.5.0.source.tar.xz b/thunderbird-78.5.0.source.tar.xz
deleted file mode 100644
index 4a9eddb..0000000
--- a/thunderbird-78.5.0.source.tar.xz
+++ /dev/null
@@ -1,3 +0,0 @@
-version https://git-lfs.github.com/spec/v1
-oid sha256:5f8a89c20e3ede73510da3eef866a1d07f31251c7912f6c52759db78f2307b77
-size 355944116
diff --git a/thunderbird-78.5.0.source.tar.xz.asc b/thunderbird-78.5.0.source.tar.xz.asc
deleted file mode 100644
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--- a/thunderbird-78.5.0.source.tar.xz.asc
+++ /dev/null
@@ -1,16 +0,0 @@
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--- /dev/null
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