diff --git a/docs/manual/mod/core.html.en b/docs/manual/mod/core.html.en
index df55e3b..2463a02 100644
--- a/docs/manual/mod/core.html.en
+++ b/docs/manual/mod/core.html.en
@@ -2933,12 +2933,19 @@ from the client</td></tr>
 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
 </table>
-    <p>Limit (in bytes) on maximum size of an XML-based request
-    body. A value of <code>0</code> will disable any checking.</p>
+    <p>Limit (in bytes) on the maximum size of an XML-based request
+    body. A value of <code>0</code> will apply a hard limit (depending on
+    32bit vs 64bit system) allowing for XML escaping within the bounds of
+    the system addressable memory, but it exists for compatibility only
+    and is not recommended since it does not account for memory consumed
+    elsewhere or concurrent requests, which might result in an overall
+    system out-of-memory.
+    </p>
 
     <p>Example:</p>
 
-    <pre class="prettyprint lang-config">LimitXMLRequestBody 0</pre>
+    <pre class="prettyprint lang-config"># Limit of 1 MiB
+    LimitXMLRequestBody 1073741824</pre>
 
 
 
diff --git a/server/core.c b/server/core.c
index 456336c..de2b0d2 100644
--- a/server/core.c
+++ b/server/core.c
@@ -70,6 +70,8 @@
 /* LimitXMLRequestBody handling */
 #define AP_LIMIT_UNSET                  ((long) -1)
 #define AP_DEFAULT_LIMIT_XML_BODY       ((apr_size_t)1000000)
+/* Hard limit for ap_escape_html2() */
+#define AP_MAX_LIMIT_XML_BODY           ((apr_size_t)(APR_SIZE_MAX / 6 - 1))
 
 #define AP_MIN_SENDFILE_BYTES           (256)
 
@@ -3686,6 +3688,11 @@ static const char *set_limit_xml_req_body(cmd_parms *cmd, void *conf_,
     if (conf->limit_xml_body < 0)
         return "LimitXMLRequestBody requires a non-negative integer.";
 
+    /* zero is AP_MAX_LIMIT_XML_BODY (implicitly) */
+    if ((apr_size_t)conf->limit_xml_body > AP_MAX_LIMIT_XML_BODY)
+        return apr_psprintf(cmd->pool, "LimitXMLRequestBody must not exceed "
+                            "%" APR_SIZE_T_FMT, AP_MAX_LIMIT_XML_BODY);
+
     return NULL;
 }
 
@@ -3774,6 +3781,8 @@ AP_DECLARE(apr_size_t) ap_get_limit_xml_body(const request_rec *r)
     conf = ap_get_core_module_config(r->per_dir_config);
     if (conf->limit_xml_body == AP_LIMIT_UNSET)
         return AP_DEFAULT_LIMIT_XML_BODY;
+    if (conf->limit_xml_body == 0)
+        return AP_MAX_LIMIT_XML_BODY;
 
     return (apr_size_t)conf->limit_xml_body;
 }
diff --git a/server/util.c b/server/util.c
index e53bdc1..263270e 100644
--- a/server/util.c
+++ b/server/util.c
@@ -2037,11 +2037,14 @@ AP_DECLARE(char *) ap_escape_urlencoded(apr_pool_t *p, const char *buffer)
 
 AP_DECLARE(char *) ap_escape_html2(apr_pool_t *p, const char *s, int toasc)
 {
-    int i, j;
+    apr_size_t i, j;
     char *x;
 
     /* first, count the number of extra characters */
-    for (i = 0, j = 0; s[i] != '\0'; i++)
+    for (i = 0, j = 0; s[i] != '\0'; i++) {
+        if (i + j > APR_SIZE_MAX - 6) {
+            abort();
+        }
         if (s[i] == '<' || s[i] == '>')
             j += 3;
         else if (s[i] == '&')
@@ -2050,6 +2053,7 @@ AP_DECLARE(char *) ap_escape_html2(apr_pool_t *p, const char *s, int toasc)
             j += 5;
         else if (toasc && !apr_isascii(s[i]))
             j += 5;
+    }
 
     if (j == 0)
         return apr_pstrmemdup(p, s, i);
diff --git a/server/util_xml.c b/server/util_xml.c
index 4845194..22806fa 100644
--- a/server/util_xml.c
+++ b/server/util_xml.c
@@ -85,7 +85,7 @@ AP_DECLARE(int) ap_xml_parse_input(request_rec * r, apr_xml_doc **pdoc)
             }
 
             total_read += len;
-            if (limit_xml_body && total_read > limit_xml_body) {
+            if (total_read > limit_xml_body) {
                 ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(00539)
                               "XML request body is larger than the configured "
                               "limit of %lu", (unsigned long)limit_xml_body);