diff -Nru libde265-1.0.12/debian/changelog libde265-1.0.12/debian/changelog
--- libde265-1.0.12/debian/changelog	2024-03-01 09:32:46.000000000 +0000
+++ libde265-1.0.12/debian/changelog	2024-05-06 19:17:15.000000000 +0000
@@ -1,3 +1,12 @@
+libde265 (1.0.12-2ubuntu0.2) mantic-security; urgency=medium
+
+  * SECURITY UPDATE: denial of service
+    - debian/patches/CVE-2023-51792.patch: check validity of conformance
+      window parameters.
+    - CVE-2023-51792
+
+ -- Fabian Toepfer <fabian.toepfer@canonical.com>  Mon, 06 May 2024 21:17:15 +0200
+
 libde265 (1.0.12-2ubuntu0.1) mantic-security; urgency=medium
 
   * SECURITY UPDATE: buffer overflow
diff -Nru libde265-1.0.12/debian/patches/CVE-2023-51792.patch libde265-1.0.12/debian/patches/CVE-2023-51792.patch
--- libde265-1.0.12/debian/patches/CVE-2023-51792.patch	1970-01-01 00:00:00.000000000 +0000
+++ libde265-1.0.12/debian/patches/CVE-2023-51792.patch	2024-04-27 09:06:20.000000000 +0000
@@ -0,0 +1,28 @@
+From 221e767136b8c46c748ae35b79ec9b976b3da301 Mon Sep 17 00:00:00 2001
+From: Dirk Farin <dirk.farin@gmail.com>
+Date: Sat, 4 Nov 2023 15:13:36 +0100
+Subject: [PATCH] check validity of conformance window parameters (fixes #427)
+
+---
+ libde265/image.cc | 8 ++++++++
+ 1 file changed, 8 insertions(+)
+
+diff --git a/libde265/image.cc b/libde265/image.cc
+index c28c5771..4876b05b 100644
+--- a/libde265/image.cc
++++ b/libde265/image.cc
+@@ -330,6 +330,14 @@ de265_error de265_image::alloc_image(int w,int h, enum de265_chroma c,
+   int top    = sps ? sps->conf_win_top_offset : 0;
+   int bottom = sps ? sps->conf_win_bottom_offset : 0;
+ 
++  if ((left+right)*WinUnitX >= width) {
++    return DE265_ERROR_CODED_PARAMETER_OUT_OF_RANGE;
++  }
++
++  if ((top+bottom)*WinUnitX >= height) {
++    return DE265_ERROR_CODED_PARAMETER_OUT_OF_RANGE;
++  }
++
+   width_confwin = width - (left+right)*WinUnitX;
+   height_confwin= height- (top+bottom)*WinUnitY;
+   chroma_width_confwin = chroma_width -left-right;
diff -Nru libde265-1.0.12/debian/patches/series libde265-1.0.12/debian/patches/series
--- libde265-1.0.12/debian/patches/series	2024-03-01 09:32:46.000000000 +0000
+++ libde265-1.0.12/debian/patches/series	2024-04-27 09:06:20.000000000 +0000
@@ -8,3 +8,4 @@
 CVE-2023-49465.patch
 CVE-2023-49467.patch
 CVE-2023-49468.patch
+CVE-2023-51792.patch