diff --git a/src/lib/ares__buf.c b/src/lib/ares__buf.c
index 0663383d..2203662f 100644
--- a/src/lib/ares__buf.c
+++ b/src/lib/ares__buf.c
@@ -941,9 +941,9 @@ ares_status_t ares__buf_set_position(ares__buf_t *buf, size_t idx)
   return ARES_SUCCESS;
 }
 
-ares_status_t ares__buf_parse_dns_binstr(ares__buf_t *buf, size_t remaining_len,
-                                         unsigned char **bin, size_t *bin_len,
-                                         ares_bool_t allow_multiple)
+static ares_status_t ares__buf_parse_dns_binstr_int(
+  ares__buf_t *buf, size_t remaining_len, unsigned char **bin, size_t *bin_len,
+  ares_bool_t allow_multiple, ares_bool_t validate_printable)
 {
   unsigned char len;
   ares_status_t status;
@@ -970,7 +970,17 @@ ares_status_t ares__buf_parse_dns_binstr(ares__buf_t *buf, size_t remaining_len,
     }
 
     if (len) {
-      /* XXX: Maybe we should scan to make sure it is printable? */
+      /* When used by the _str() parser, it really needs to be validated to
+       * be a valid printable ascii string.  Do that here */
+      if (validate_printable && ares__buf_len(buf) >= len) {
+        size_t      mylen;
+        const char *data = (const char *)ares__buf_peek(buf, &mylen);
+        if (!ares__str_isprint(data, len)) {
+          status = ARES_EBADSTR;
+          break;
+        }
+      }
+
       if (bin != NULL) {
         status = ares__buf_fetch_bytes_into_buf(buf, binbuf, len);
       } else {
@@ -1003,12 +1013,21 @@ ares_status_t ares__buf_parse_dns_binstr(ares__buf_t *buf, size_t remaining_len,
   return status;
 }
 
+ares_status_t ares__buf_parse_dns_binstr(ares__buf_t *buf, size_t remaining_len,
+                                         unsigned char **bin, size_t *bin_len,
+                                         ares_bool_t allow_multiple)
+{
+  return ares__buf_parse_dns_binstr_int(buf, remaining_len, bin, bin_len,
+                                        allow_multiple, ARES_FALSE);
+}
+
 ares_status_t ares__buf_parse_dns_str(ares__buf_t *buf, size_t remaining_len,
                                       char **str, ares_bool_t allow_multiple)
 {
   size_t len;
-  return ares__buf_parse_dns_binstr(buf, remaining_len, (unsigned char **)str,
-                                    &len, allow_multiple);
+
+  return ares__buf_parse_dns_binstr_int(
+    buf, remaining_len, (unsigned char **)str, &len, allow_multiple, ARES_TRUE);
 }
 
 ares_status_t ares__buf_append_num_dec(ares__buf_t *buf, size_t num, size_t len)
diff --git a/src/lib/ares_str.c b/src/lib/ares_str.c
index 5f25cfea..9483a4bc 100644
--- a/src/lib/ares_str.c
+++ b/src/lib/ares_str.c
@@ -260,6 +260,10 @@ ares_bool_t ares__is_hostnamech(int ch)
 ares_bool_t ares__is_hostname(const char *str)
 {
   size_t i;
+
+  if (str == NULL)
+    return ARES_FALSE;
+
   for (i = 0; str[i] != 0; i++) {
     if (!ares__is_hostnamech(str[i])) {
       return ARES_FALSE;
@@ -267,3 +271,18 @@ ares_bool_t ares__is_hostname(const char *str)
   }
   return ARES_TRUE;
 }
+
+ares_bool_t ares__str_isprint(const char *str, size_t len)
+{
+  size_t i;
+
+  if (str == NULL && len != 0)
+    return ARES_FALSE;
+
+  for (i = 0; i < len; i++) {
+    if (!ares__isprint(str[i])) {
+      return ARES_FALSE;
+    }
+  }
+  return ARES_TRUE;
+}
diff --git a/src/lib/ares_str.h b/src/lib/ares_str.h
index 8d869073..526a927a 100644
--- a/src/lib/ares_str.h
+++ b/src/lib/ares_str.h
@@ -62,5 +62,18 @@ ares_bool_t   ares__is_hostnamech(int ch);
 
 ares_bool_t   ares__is_hostname(const char *str);
 
+/*! Validate the string provided is printable.  The length specified must be
+ *  at least the size of the buffer provided.  If a NULL-terminator is hit
+ *  before the length provided is hit, this will not be considered a valid
+ *  printable string.  This does not validate that the string is actually
+ *  NULL terminated.
+ *
+ *  \param[in] str  Buffer containing string to evaluate.
+ *  \param[in] len  Number of characters to evaluate within provided buffer.
+ *                  If 0, will return TRUE since it did not hit an exception.
+ *  \return ARES_TRUE if the entire string is printable, ARES_FALSE if not.
+ */
+ares_bool_t   ares__str_isprint(const char *str, size_t len);
+
 
 #endif /* __ARES_STR_H */