diff --git a/debian/changelog b/debian/changelog
index 5655c0f2a03e782d4a27855e6036e363d56c4612..9c07ed253e6a5212a5da9ac6bc2d77435234154c 100644
--- a/debian/changelog
+++ b/debian/changelog
@@ -1,3 +1,12 @@
+xorg-server (2:1.20.11-1+deb11u9) bullseye-security; urgency=high
+
+ * Non-maintainer upload by the Security Team.
+ * Xi: allocate enough XkbActions for our buttons (CVE-2023-6377)
+ * randr: avoid integer truncation in length check of ProcRRChange*Property
+ (CVE-2023-6478)
+
+ -- Salvatore Bonaccorso <carnil@debian.org> Sat, 09 Dec 2023 12:19:55 +0100
+
xorg-server (2:1.20.11-1+deb11u8+apertis1) apertis; urgency=medium
* Sync updates from Debian Bullseye Security.
diff --git a/debian/patches/Xi-allocate-enough-XkbActions-for-our-buttons.patch b/debian/patches/Xi-allocate-enough-XkbActions-for-our-buttons.patch
new file mode 100644
index 0000000000000000000000000000000000000000..558eb6f0de28eab05242e73efb9ac68439e48518
--- /dev/null
+++ b/debian/patches/Xi-allocate-enough-XkbActions-for-our-buttons.patch
@@ -0,0 +1,75 @@
+From ff830d3c47c92e7c810055b9fd56ae22fc1d5346 Mon Sep 17 00:00:00 2001
+From: Peter Hutterer <peter.hutterer@who-t.net>
+Date: Tue, 28 Nov 2023 15:19:04 +1000
+Subject: [PATCH xserver] Xi: allocate enough XkbActions for our buttons
+
+button->xkb_acts is supposed to be an array sufficiently large for all
+our buttons, not just a single XkbActions struct. Allocating
+insufficient memory here means when we memcpy() later in
+XkbSetDeviceInfo we write into memory that wasn't ours to begin with,
+leading to the usual security ooopsiedaisies.
+
+CVE-2023-6377, ZDI-CAN-22412, ZDI-CAN-22413
+
+This vulnerability was discovered by:
+Jan-Niklas Sohn working with Trend Micro Zero Day Initiative
+---
+ Xi/exevents.c | 8 ++++++--
+ dix/devices.c | 11 +++++++++++
+ 2 files changed, 17 insertions(+), 2 deletions(-)
+
+diff --git a/Xi/exevents.c b/Xi/exevents.c
+index dcd4efb3bc..f24de9eec4 100644
+--- a/Xi/exevents.c
++++ b/Xi/exevents.c
+@@ -612,12 +612,16 @@ DeepCopyPointerClasses(DeviceIntPtr from, DeviceIntPtr to)
+
+ if (from->button->xkb_acts) {
+ if (!to->button->xkb_acts) {
+- to->button->xkb_acts = calloc(1, sizeof(XkbAction));
++ to->button->xkb_acts = calloc(from->button->numButtons, sizeof(XkbAction));
+ if (!to->button->xkb_acts)
+ FatalError("[Xi] not enough memory for xkb_acts.\n");
++ } else {
++ to->button->xkb_acts = xnfreallocarray(to->button->xkb_acts,
++ from->button->numButtons,
++ sizeof(XkbAction));
+ }
+ memcpy(to->button->xkb_acts, from->button->xkb_acts,
+- sizeof(XkbAction));
++ from->button->numButtons * sizeof(XkbAction));
+ }
+ else {
+ free(to->button->xkb_acts);
+diff --git a/dix/devices.c b/dix/devices.c
+index 7150734a58..deb3010206 100644
+--- a/dix/devices.c
++++ b/dix/devices.c
+@@ -2530,6 +2530,8 @@ RecalculateMasterButtons(DeviceIntPtr slave)
+
+ if (master->button && master->button->numButtons != maxbuttons) {
+ int i;
++ int last_num_buttons = master->button->numButtons;
++
+ DeviceChangedEvent event = {
+ .header = ET_Internal,
+ .type = ET_DeviceChanged,
+@@ -2540,6 +2542,15 @@ RecalculateMasterButtons(DeviceIntPtr slave)
+ };
+
+ master->button->numButtons = maxbuttons;
++ if (last_num_buttons < maxbuttons) {
++ master->button->xkb_acts = xnfreallocarray(master->button->xkb_acts,
++ maxbuttons,
++ sizeof(XkbAction));
++ memset(&master->button->xkb_acts[last_num_buttons],
++ 0,
++ (maxbuttons - last_num_buttons) * sizeof(XkbAction));
++ }
++
+
+ memcpy(&event.buttons.names, master->button->labels, maxbuttons *
+ sizeof(Atom));
+--
+2.43.0
+
diff --git a/debian/patches/randr-avoid-integer-truncation-in-length-check-of-Pr.patch b/debian/patches/randr-avoid-integer-truncation-in-length-check-of-Pr.patch
new file mode 100644
index 0000000000000000000000000000000000000000..1f855be0aef500fd3c56833fd370640105e1cf5f
--- /dev/null
+++ b/debian/patches/randr-avoid-integer-truncation-in-length-check-of-Pr.patch
@@ -0,0 +1,59 @@
+From 3e0222fcae552685d423914a683c1709dc5f6d6b Mon Sep 17 00:00:00 2001
+From: Peter Hutterer <peter.hutterer@who-t.net>
+Date: Mon, 27 Nov 2023 16:27:49 +1000
+Subject: [PATCH xserver] randr: avoid integer truncation in length check of
+ ProcRRChange*Property
+
+Affected are ProcRRChangeProviderProperty and ProcRRChangeOutputProperty.
+See also xserver@8f454b79 where this same bug was fixed for the core
+protocol and XI.
+
+This fixes an OOB read and the resulting information disclosure.
+
+Length calculation for the request was clipped to a 32-bit integer. With
+the correct stuff->nUnits value the expected request size was
+truncated, passing the REQUEST_FIXED_SIZE check.
+
+The server then proceeded with reading at least stuff->num_items bytes
+(depending on stuff->format) from the request and stuffing whatever it
+finds into the property. In the process it would also allocate at least
+stuff->nUnits bytes, i.e. 4GB.
+
+CVE-2023-6478, ZDI-CAN-22561
+
+This vulnerability was discovered by:
+Jan-Niklas Sohn working with Trend Micro Zero Day Initiative
+---
+ randr/rrproperty.c | 2 +-
+ randr/rrproviderproperty.c | 2 +-
+ 2 files changed, 2 insertions(+), 2 deletions(-)
+
+diff --git a/randr/rrproperty.c b/randr/rrproperty.c
+index 25469f57b2..c4fef8a1f6 100644
+--- a/randr/rrproperty.c
++++ b/randr/rrproperty.c
+@@ -530,7 +530,7 @@ ProcRRChangeOutputProperty(ClientPtr client)
+ char format, mode;
+ unsigned long len;
+ int sizeInBytes;
+- int totalSize;
++ uint64_t totalSize;
+ int err;
+
+ REQUEST_AT_LEAST_SIZE(xRRChangeOutputPropertyReq);
+diff --git a/randr/rrproviderproperty.c b/randr/rrproviderproperty.c
+index b79c17f9bf..90c5a9a933 100644
+--- a/randr/rrproviderproperty.c
++++ b/randr/rrproviderproperty.c
+@@ -498,7 +498,7 @@ ProcRRChangeProviderProperty(ClientPtr client)
+ char format, mode;
+ unsigned long len;
+ int sizeInBytes;
+- int totalSize;
++ uint64_t totalSize;
+ int err;
+
+ REQUEST_AT_LEAST_SIZE(xRRChangeProviderPropertyReq);
+--
+2.43.0
+
diff --git a/debian/patches/series b/debian/patches/series
index 83e6d3f4d8bbedf63cb6af6f84c1c53f3163226c..edb34532ea4854234d8bacbd0b155f86dc22eed6 100644
--- a/debian/patches/series
+++ b/debian/patches/series
@@ -24,3 +24,5 @@ disable-libgl-in-xwayland.patch
21_composite-Fix-use-after-free-of-the-COW.patch
0001-Xi-randr-fix-handling-of-PropModeAppend-Prepend.patch
0002-mi-reset-the-PointerWindows-reference-on-screen-swit.patch
+Xi-allocate-enough-XkbActions-for-our-buttons.patch
+randr-avoid-integer-truncation-in-length-check-of-Pr.patch