Commit df934b472 for imagemagick.org

commit df934b4721173f8dda33c6d007f9811669640e86
Author: Dirk Lemstra <dirk@lemstra.org>
Date:   Sat Mar 7 10:14:57 2026 +0100

    Added extra check to prevent out of bounds write when color reduction fails (GHSA-49hx-7656-jpg3)

diff --git a/coders/sixel.c b/coders/sixel.c
index 2eddc7ce8..2b7514137 100644
--- a/coders/sixel.c
+++ b/coders/sixel.c
@@ -1399,6 +1399,8 @@ static MagickBooleanType WriteSIXELImage(const ImageInfo *image_info,
           image->colormap[opacity].blue=image->transparent_color.blue;
         }
     }
+  if (image->colors > SIXEL_PALETTE_MAX)
+    return(MagickFalse);
   /*
     SIXEL header.
   */