diff --git a/SOURCES/qtbase-fix-buffer-overflow-in-xbm-parser.patch b/SOURCES/qtbase-fix-buffer-overflow-in-xbm-parser.patch
new file mode 100644
index 0000000..b1fe825
--- /dev/null
+++ b/SOURCES/qtbase-fix-buffer-overflow-in-xbm-parser.patch
@@ -0,0 +1,69 @@
+diff --git a/src/gui/image/qxbmhandler.cpp b/src/gui/image/qxbmhandler.cpp
+index 155a4f88..39bffc89 100644
+--- a/src/gui/image/qxbmhandler.cpp
++++ b/src/gui/image/qxbmhandler.cpp
+@@ -154,7 +154,9 @@ static bool read_xbm_body(QIODevice *device, int w, int h, QImage *outImage)
+     w = (w+7)/8;                                // byte width
+ 
+     while (y < h) {                                // for all encoded bytes...
+-        if (p) {                                // p = "0x.."
++        if (p && p < (buf + readBytes - 3)) {      // p = "0x.."
++            if (!isxdigit(p[2]) || !isxdigit(p[3]))
++                return false;
+             *b++ = hex2byte(p+2);
+             p += 2;
+             if (++x == w && ++y < h) {
+diff --git a/tests/auto/gui/image/qimagereader/tst_qimagereader.cpp b/tests/auto/gui/image/qimagereader/tst_qimagereader.cpp
+index 170f551d..0f6c91bd 100644
+--- a/tests/auto/gui/image/qimagereader/tst_qimagereader.cpp
++++ b/tests/auto/gui/image/qimagereader/tst_qimagereader.cpp
+@@ -164,6 +164,7 @@ private slots:
+     void preserveTexts_data();
+     void preserveTexts();
+ 
++    void xbmBufferHandling();
+ private:
+     QString prefix;
+     QTemporaryDir m_temporaryDir;
+@@ -1967,5 +1968,41 @@ void tst_QImageReader::preserveTexts()
+ }
+ 
+ 
++void tst_QImageReader::xbmBufferHandling()
++{
++    uint8_t original_buffer[256];
++    for (int i = 0; i < 256; ++i)
++        original_buffer[i] = i;
++
++    QImage image(original_buffer, 256, 8, QImage::Format_MonoLSB);
++    image.setColorTable({0xff000000, 0xffffffff});
++
++    QByteArray buffer;
++    {
++        QBuffer buf(&buffer);
++        QImageWriter writer(&buf, "xbm");
++        writer.write(image);
++    }
++
++    QCOMPARE(QImage::fromData(buffer, "xbm"), image);
++
++    auto i = buffer.indexOf(',');
++    buffer.insert(i + 1, "                                                                                ");
++    QCOMPARE(QImage::fromData(buffer, "xbm"), image);
++    buffer.insert(i + 1, "                                                                                ");
++    QCOMPARE(QImage::fromData(buffer, "xbm"), image);
++    buffer.insert(i + 1, "                                                                              ");
++#if 0   // Lines longer than 300 chars not supported currently
++    QCOMPARE(QImage::fromData(buffer, "xbm"), image);
++#endif
++
++    i = buffer.lastIndexOf("\n ");
++    buffer.truncate(i + 1);
++    buffer.append(QByteArray(297, ' '));
++    buffer.append("0x");
++    // Only check we get no buffer overflow
++    QImage::fromData(buffer, "xbm");
++}
++
+ QTEST_MAIN(tst_QImageReader)
+ #include "tst_qimagereader.moc"
diff --git a/SPECS/qt5-qtbase.spec b/SPECS/qt5-qtbase.spec
index c378a04..e5ad5f3 100644
--- a/SPECS/qt5-qtbase.spec
+++ b/SPECS/qt5-qtbase.spec
@@ -57,7 +57,7 @@ BuildRequires: pkgconfig(libsystemd)
 Summary: Qt5 - QtBase components
 Name:    qt5-qtbase
 Version: 5.9.7
-Release: 4%{?dist}
+Release: 5%{?dist}
 
 # See LGPL_EXCEPTIONS.txt, for exception details
 License: LGPLv2 with exceptions or GPLv3 with exceptions
@@ -115,6 +115,9 @@ Patch200: qtbase-qlibrary-do-not-attempt-to-load-library-relative-to-pwd.patch
 # CVE-2020-0569 qt5-qtbase: qt: files placed by attacker can influence the working directory and lead to malicious code execution
 Patch201: qtbase-do-not-load-plugin-from-pwd.patch
 
+# CVE-2020-17507 qt5-qtbase: qt: buffer over-read in read_xbm_body in gui/image/qxbmhandler.cpp
+Patch202: qtbase-fix-buffer-overflow-in-xbm-parser.patch
+
 # Do not check any files in %%{_qt5_plugindir}/platformthemes/ for requires.
 # Those themes are there for platform integration. If the required libraries are
 # not there, the platform to integrate with isn't either. Then Qt will just
@@ -382,6 +385,7 @@ RPM macros for building Qt5 packages.
 # Security fixes
 %patch200 -p1 -b .qlibrary-do-not-attempt-to-load-library-relative-to-pwd
 %patch201 -p1 -b .do-not-load-plugin-from-pwd
+%patch202 -p1 -b .fix-buffer-overflow-in-xbm-parser
 
 %if 0%{?inject_optflags}
 ## adjust $RPM_OPT_FLAGS
@@ -1037,6 +1041,10 @@ fi
 
 
 %changelog
+* Thu Sep 24 2020 Jan Grulich <jgrulich@redhat.com> - 5.9.7-5
+- Fix buffer overflow in XBM parser
+  Resolves: bz#1870365
+
 * Tue May 19 2020 Jan Grulich <jgrulich@redhat.com> - 5.9.7-4
 - Fix: Files placed by attacker can influence the working directory and lead to malicious code execution
   Resolves: bz#1814740