diff -urNp old/plug-ins/common/file-psp.c new/plug-ins/common/file-psp.c
--- old/plug-ins/common/file-psp.c	2018-01-04 11:58:46.928253797 +0100
+++ new/plug-ins/common/file-psp.c	2018-01-04 12:03:42.141874067 +0100
@@ -913,6 +913,12 @@ read_creator_block (FILE     *f,
               g_message ("Error reading creator keyword data");
               return -1;
             }
+          if (string[length - 1] != '\0')
+            {
+              g_message ("Creator keyword data not nul-terminated");
+              g_free (string);
+              return -1;
+            }
           switch (keyword)
             {
             case PSP_CRTR_FLD_CRT_DATE: