diff --git a/debian/changelog b/debian/changelog
index 7191081..912d958 100644
--- a/debian/changelog
+++ b/debian/changelog
@@ -1,11 +1,17 @@
-qpdf (9.1.1-ok2) yangtze; urgency=medium
-
-  * Update version.
-
- -- zhouganqing <zhouganqing@kylinos.cn>  Mon, 15 Aug 2022 17:00:51 +0800
-
-qpdf (9.1.1-ok1) yangtze; urgency=medium
-
-  * Build for openKylin.
-
- -- openKylinBot <openKylinBot@openkylin.com>  Mon, 25 Apr 2022 22:03:04 +0800
+qpdf (9.1.1-ok3) yangtze; urgency=medium
+
+  * omelette-guo CVE-2021-36978 安全更新：当某个下游写操作失败时，QPDF中存在基于堆的缓冲区溢出漏洞
+
+ -- lichaoheng <o_o@bupt.edu.cn>  Tue, 14 Mar 2023 11:06:54 +0800
+
+qpdf (9.1.1-ok2) yangtze; urgency=medium
+
+  * Update version.
+
+ -- zhouganqing <zhouganqing@kylinos.cn>  Mon, 15 Aug 2022 17:00:51 +0800
+
+qpdf (9.1.1-ok1) yangtze; urgency=medium
+
+  * Build for openKylin.
+
+ -- openKylinBot <openKylinBot@openkylin.com>  Mon, 25 Apr 2022 22:03:04 +0800
diff --git a/debian/patches/0001-CVE-2021-36978-QPDF.patch b/debian/patches/0001-CVE-2021-36978-QPDF.patch
new file mode 100644
index 0000000..d6a3e92
--- /dev/null
+++ b/debian/patches/0001-CVE-2021-36978-QPDF.patch
@@ -0,0 +1,80 @@
+From: lch <32248802@qq.com>
+Date: Tue, 14 Mar 2023 11:09:22 +0800
+Subject: =?utf-8?b?Q1ZFLTIwMjEtMzY5Nzgg5a6J5YWo5pu05paw77ya5b2T5p+Q5Liq5LiL?=
+ =?utf-8?b?5ri45YaZ5pON5L2c5aSx6LSl5pe277yMUVBERuS4reWtmOWcqOWfuuS6juWghg==?=
+ =?utf-8?b?55qE57yT5Yay5Yy65rqi5Ye65ryP5rSe?=
+
+---
+ libqpdf/Pl_AES_PDF.cc         | 2 +-
+ libqpdf/Pl_ASCII85Decoder.cc  | 7 +++++--
+ libqpdf/Pl_ASCIIHexDecoder.cc | 6 ++++--
+ libqpdf/Pl_Count.cc           | 2 +-
+ 4 files changed, 11 insertions(+), 6 deletions(-)
+
+diff --git a/libqpdf/Pl_AES_PDF.cc b/libqpdf/Pl_AES_PDF.cc
+index 18cf3a4..2865f80 100644
+--- a/libqpdf/Pl_AES_PDF.cc
++++ b/libqpdf/Pl_AES_PDF.cc
+@@ -238,6 +238,6 @@ Pl_AES_PDF::flush(bool strip_padding)
+ 	    }
+ 	}
+     }
+-    getNext()->write(this->outbuf, bytes);
+     this->offset = 0;
++    getNext()->write(this->outbuf, bytes);
+ }
+diff --git a/libqpdf/Pl_ASCII85Decoder.cc b/libqpdf/Pl_ASCII85Decoder.cc
+index b8df3e8..9d9f670 100644
+--- a/libqpdf/Pl_ASCII85Decoder.cc
++++ b/libqpdf/Pl_ASCII85Decoder.cc
+@@ -119,10 +119,13 @@ Pl_ASCII85Decoder::flush()
+ 
+     QTC::TC("libtests", "Pl_ASCII85Decoder partial flush",
+ 	    (this->pos == 5) ? 0 : 1);
+-    getNext()->write(outbuf, this->pos - 1);
+-
++    // Reset before calling getNext()->write in case that throws an
++    // exception.
++    auto t = this->pos - 1;
+     this->pos = 0;
+     memset(this->inbuf, 117, 5);
++
++    getNext()->write(outbuf, t);
+ }
+ 
+ void
+diff --git a/libqpdf/Pl_ASCIIHexDecoder.cc b/libqpdf/Pl_ASCIIHexDecoder.cc
+index f20a976..7845268 100644
+--- a/libqpdf/Pl_ASCIIHexDecoder.cc
++++ b/libqpdf/Pl_ASCIIHexDecoder.cc
+@@ -97,12 +97,14 @@ Pl_ASCIIHexDecoder::flush()
+ 
+     QTC::TC("libtests", "Pl_ASCIIHexDecoder partial flush",
+ 	    (this->pos == 2) ? 0 : 1);
+-    getNext()->write(&ch, 1);
+-
++    // Reset before calling getNext()->write in case that throws an
++    // exception.
+     this->pos = 0;
+     this->inbuf[0] = '0';
+     this->inbuf[1] = '0';
+     this->inbuf[2] = '\0';
++
++    getNext()->write(&ch, 1);
+ }
+ 
+ void
+diff --git a/libqpdf/Pl_Count.cc b/libqpdf/Pl_Count.cc
+index 8077092..c35619b 100644
+--- a/libqpdf/Pl_Count.cc
++++ b/libqpdf/Pl_Count.cc
+@@ -27,8 +27,8 @@ Pl_Count::write(unsigned char* buf, size_t len)
+     if (len)
+     {
+ 	this->m->count += QIntC::to_offset(len);
+-	getNext()->write(buf, len);
+ 	this->m->last_char = buf[len - 1];
++	getNext()->write(buf, len);
+     }
+ }
+ 
diff --git a/debian/patches/series b/debian/patches/series
new file mode 100644
index 0000000..93ccb3a
--- /dev/null
+++ b/debian/patches/series
@@ -0,0 +1 @@
+0001-CVE-2021-36978-QPDF.patch