diff --git a/client/X11/xf_client.c b/client/X11/xf_client.c
index ca7179949..9100ed463 100644
--- a/client/X11/xf_client.c
+++ b/client/X11/xf_client.c
@@ -834,14 +834,13 @@ void xf_unlock_x11_(xfContext* xfc, const char* fkt)
 static BOOL xf_get_pixmap_info(xfContext* xfc)
 {
 	int i;
-	int vi_count;
-	int pf_count;
-	XVisualInfo* vi;
-	XVisualInfo* vis;
-	XVisualInfo tpl;
-	XPixmapFormatValues* pf;
-	XPixmapFormatValues* pfs;
-	XWindowAttributes window_attributes;
+	int vi_count = 0;
+	int pf_count = 0;
+	XVisualInfo* vi = NULL;
+	XVisualInfo* vis = NULL;
+	XVisualInfo tpl = { 0 };
+	XPixmapFormatValues* pfs = NULL;
+	XWindowAttributes window_attributes = { 0 };
 	WINPR_ASSERT(xfc->display);
 	pfs = XListPixmapFormats(xfc->display, &pf_count);
 
@@ -853,7 +852,7 @@ static BOOL xf_get_pixmap_info(xfContext* xfc)
 
 	for (i = 0; i < pf_count; i++)
 	{
-		pf = pfs + i;
+		const XPixmapFormatValues* pf = &pfs[i];
 
 		if (pf->depth == xfc->depth)
 		{
@@ -863,7 +862,7 @@ static BOOL xf_get_pixmap_info(xfContext* xfc)
 	}
 
 	XFree(pfs);
-	ZeroMemory(&tpl, sizeof(tpl));
+
 	tpl.class = TrueColor;
 	tpl.screen = xfc->screen_number;
 
@@ -1953,7 +1952,8 @@ static BOOL xfreerdp_client_new(freerdp* instance, rdpContext* context)
 		if ((status == Success) && (actual_type == XA_ATOM) && (actual_format == 32))
 		{
 			xfc->supportedAtomCount = nitems;
-			xfc->supportedAtoms = calloc(nitems, sizeof(Atom));
+			xfc->supportedAtoms = calloc(xfc->supportedAtomCount, sizeof(Atom));
+			WINPR_ASSERT(xfc->supportedAtoms);
 			memcpy(xfc->supportedAtoms, data, nitems * sizeof(Atom));
 		}
 
diff --git a/client/X11/xf_monitor.c b/client/X11/xf_monitor.c
index 8d7e47c3a..f02dbade5 100644
--- a/client/X11/xf_monitor.c
+++ b/client/X11/xf_monitor.c
@@ -136,14 +136,14 @@ BOOL xf_detect_monitors(xfContext* xfc, UINT32* pMaxWidth, UINT32* pMaxHeight)
 	int nmonitors = 0;
 	int monitor_index = 0;
 	BOOL primaryMonitorFound = FALSE;
-	VIRTUAL_SCREEN* vscreen;
-	rdpSettings* settings;
-	int mouse_x, mouse_y, _dummy_i;
-	Window _dummy_w;
+	VIRTUAL_SCREEN* vscreen = NULL;
+	rdpSettings* settings = NULL;
+	int mouse_x = 0, mouse_y = 0, _dummy_i = 0;
+	Window _dummy_w = 0;
 	int current_monitor = 0;
-	Screen* screen;
+	Screen* screen = NULL;
 #if defined WITH_XINERAMA || defined WITH_XRANDR
-	int major, minor;
+	int major = 0, minor = 0;
 #endif
 #if defined(USABLE_XRANDR)
 	XRRMonitorInfo* rrmonitors = NULL;
diff --git a/client/X11/xf_window.c b/client/X11/xf_window.c
index 5ec165396..5d48248d3 100644
--- a/client/X11/xf_window.c
+++ b/client/X11/xf_window.c
@@ -345,9 +345,9 @@ void xf_SetWindowFullscreen(xfContext* xfc, xfWindow* window, BOOL fullscreen)
 BOOL xf_GetWindowProperty(xfContext* xfc, Window window, Atom property, int length,
                           unsigned long* nitems, unsigned long* bytes, BYTE** prop)
 {
-	int status;
-	Atom actual_type;
-	int actual_format;
+	int status = 0;
+	Atom actual_type = None;
+	int actual_format = 0;
 
 	if (property == None)
 		return FALSE;
diff --git a/libfreerdp/core/settings.c b/libfreerdp/core/settings.c
index cf2c4adcd..c4f78a04a 100644
--- a/libfreerdp/core/settings.c
+++ b/libfreerdp/core/settings.c
@@ -248,7 +248,7 @@ static void settings_load_hkey_local_machine(rdpSettings* settings)
 
 static BOOL settings_get_computer_name(rdpSettings* settings)
 {
-	CHAR computerName[256];
+	CHAR computerName[256] = { 0 };
 	DWORD nSize = sizeof(computerName);
 
 	if (!GetComputerNameExA(ComputerNameNetBIOS, computerName, &nSize))
diff --git a/libfreerdp/locale/keyboard_xkbfile.c b/libfreerdp/locale/keyboard_xkbfile.c
index 047782a0e..bdf9a390d 100644
--- a/libfreerdp/locale/keyboard_xkbfile.c
+++ b/libfreerdp/locale/keyboard_xkbfile.c
@@ -383,12 +383,12 @@ static char* comma_substring(char* s, int n)
 
 int detect_keyboard_layout_from_xkbfile(void* display, DWORD* keyboardLayoutId)
 {
-	char* layout;
-	char* variant;
+	char* layout = NULL;
+	char* variant = NULL;
 	DWORD group = 0;
-	XkbStateRec state;
+	XkbStateRec state = { 0 };
 	XKeyboardState coreKbdState;
-	XkbRF_VarDefsRec rules_names;
+	XkbRF_VarDefsRec rules_names = { 0 };
 
 	DEBUG_KBD("display: %p", display);
 
diff --git a/winpr/libwinpr/utils/wlog/wlog.c b/winpr/libwinpr/utils/wlog/wlog.c
index 3fba3cc82..c9e20f14f 100644
--- a/winpr/libwinpr/utils/wlog/wlog.c
+++ b/winpr/libwinpr/utils/wlog/wlog.c
@@ -375,7 +375,7 @@ BOOL WLog_PrintMessageVA(wLog* log, DWORD type, DWORD level, size_t line, const
 			}
 			else
 			{
-				char formattedLogMessage[WLOG_MAX_STRING_SIZE];
+				char formattedLogMessage[WLOG_MAX_STRING_SIZE] = { 0 };
 
 				if (wvsnprintfx(formattedLogMessage, WLOG_MAX_STRING_SIZE - 1, message.FormatString,
 				                args) < 0)