diff --git a/CHANGELOG.md b/CHANGELOG.md
index a052d744..7e7aa4a4 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -82,10 +82,14 @@
   support the offered mime-types ([#1092][1092]).
 * Keyboard enter/leave events being ignored if there is no keymap
   ([#1097][1097]).
+* Crash when application emitted an invalid `CSI 38;5;<idx>m`, `CSI
+  38:5:<idx>m`, `CSI 48;5;<idx>m` or `CSI 48:5:<idx>m` sequence
+  ([#1111][1111]).
 
 [1055]: https://codeberg.org/dnkl/foot/issues/1055
 [1092]: https://codeberg.org/dnkl/foot/issues/1092
 [1097]: https://codeberg.org/dnkl/foot/issues/1097
+[1111]: https://codeberg.org/dnkl/foot/issues/1111
 
 
 ### Security
diff --git a/csi.c b/csi.c
index 57cae6b3..659839f0 100644
--- a/csi.c
+++ b/csi.c
@@ -128,7 +128,8 @@ csi_sgr(struct terminal *term)
                 term->vt.params.v[i + 1].value == 5)
             {
                 src = COLOR_BASE256;
-                color = term->vt.params.v[i + 2].value;
+                color = min(term->vt.params.v[i + 2].value,
+                            ALEN(term->colors.table) - 1);
                 i += 2;
             }
 
@@ -149,7 +150,8 @@ csi_sgr(struct terminal *term)
                      term->vt.params.v[i].sub.value[0] == 5)
             {
                 src = COLOR_BASE256;
-                color = term->vt.params.v[i].sub.value[1];
+                color = min(term->vt.params.v[i].sub.value[1],
+                            ALEN(term->colors.table) - 1);
             }
 
             /*