diff --git a/modules/ssl/ssl_engine_kernel.c b/modules/ssl/ssl_engine_kernel.c
index 6022ef9262..a71d829e66 100644
--- a/modules/ssl/ssl_engine_kernel.c
+++ b/modules/ssl/ssl_engine_kernel.c
@@ -1401,7 +1401,7 @@ int ssl_callback_SSLVerify_CRL(int ok, X509_STORE_CTX *ctx, conn_rec *c)
 
             BIO_free(bio);
 
-            ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, s, buff);
+            ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, s, "%s", buff);
         }
 
         /*
diff --git a/server/log.c b/server/log.c
index f8c2af4204..16574ab22e 100644
--- a/server/log.c
+++ b/server/log.c
@@ -625,9 +625,9 @@ AP_DECLARE(void) ap_log_pid(apr_pool_t *p, const char *filename)
          *      based on the last modification time of the pid file.
          */
         ap_log_perror(APLOG_MARK, APLOG_WARNING, 0, p,
-                      apr_psprintf(p, "pid file %s overwritten -- Unclean "
-                                   "shutdown of previous Apache run?",
-                                   fname));
+                      "pid file %s overwritten -- Unclean "
+                      "shutdown of previous Apache run?",
+                      fname);
     }
 
     if ((rv = apr_file_open(&pid_file, fname,
diff --git a/server/mpm/prefork/prefork.c b/server/mpm/prefork/prefork.c
index 3dbbe58fff..7acd04b976 100644
--- a/server/mpm/prefork/prefork.c
+++ b/server/mpm/prefork/prefork.c
@@ -210,11 +210,11 @@ static void accept_mutex_on(void)
 
         if (ap_my_generation != 
             ap_scoreboard_image->global->running_generation) {
-            ap_log_error(APLOG_MARK, APLOG_DEBUG, rv, NULL, msg);
+            ap_log_error(APLOG_MARK, APLOG_DEBUG, rv, NULL, "%s", msg);
             clean_child_exit(0);
         }
         else {
-            ap_log_error(APLOG_MARK, APLOG_EMERG, rv, NULL, msg);
+            ap_log_error(APLOG_MARK, APLOG_EMERG, rv, NULL, "%s", msg);
             exit(APEXIT_CHILDFATAL);
         }
     }
@@ -228,14 +228,14 @@ static void accept_mutex_off(void)
 
         if (ap_my_generation != 
             ap_scoreboard_image->global->running_generation) {
-            ap_log_error(APLOG_MARK, APLOG_DEBUG, rv, NULL, msg);
+            ap_log_error(APLOG_MARK, APLOG_DEBUG, rv, NULL, "%s", msg);
             /* don't exit here... we have a connection to
              * process, after which point we'll see that the
              * generation changed and we'll exit cleanly
              */
         }
         else {
-            ap_log_error(APLOG_MARK, APLOG_EMERG, rv, NULL, msg);
+            ap_log_error(APLOG_MARK, APLOG_EMERG, rv, NULL, "%s", msg);
             exit(APEXIT_CHILDFATAL);
         }
     }
diff --git a/support/htdbm.c b/support/htdbm.c
index 652d5d793f..cdb317e3f7 100644
--- a/support/htdbm.c
+++ b/support/htdbm.c
@@ -263,7 +263,7 @@ static apr_status_t htdbm_list(htdbm_t *htdbm)
         rec[val.dsize] = '\0';
         cmnt = strchr(rec, ':');
         if (cmnt)
-            fprintf(stderr, cmnt + 1);
+            fprintf(stderr, "%s", cmnt + 1);
         fprintf(stderr, "\n");
         rv = apr_dbm_nextkey(htdbm->dbm, &key);
         if (rv != APR_SUCCESS)