diff --git a/cps/epub.py b/cps/epub.py
index 3947cee65..638462f09 100644
--- a/cps/epub.py
+++ b/cps/epub.py
@@ -175,7 +175,7 @@ def parse_epub_cover(ns, tree, epub_zip, cover_path, tmp_file_path):
     for cs in cover_section:
         if cs.endswith('.xhtml') or cs.endswith('.html'):
             markup = epub_zip.read(os.path.join(cover_path, cs))
-            markup_tree = etree.fromstring(markup)
+            markup_tree = etree.fromstring(markup, parser=etree.XMLParser(resolve_entities=False, no_network=True))
             # no matter xhtml or html with no namespace
             img_src = markup_tree.xpath("//*[local-name() = 'img']/@src")
             # Alternative image source
diff --git a/cps/epub_helper.py b/cps/epub_helper.py
index 4517f2c60..252fad313 100644
--- a/cps/epub_helper.py
+++ b/cps/epub_helper.py
@@ -53,16 +53,20 @@ def updateEpub(src, dest, filename, data, ):
         zf.writestr(filename, data)
 
 
+# Safe parser: disable entity resolution and network access to prevent XXE attacks
+_safe_parser = etree.XMLParser(resolve_entities=False, no_network=True)
+
+
 def get_content_opf(file_path, ns=None):
     if ns is None:
         ns = default_ns
     epubZip = zipfile.ZipFile(file_path)
     txt = epubZip.read('META-INF/container.xml')
-    tree = etree.fromstring(txt)
+    tree = etree.fromstring(txt, parser=_safe_parser)
     cf_name = tree.xpath('n:rootfiles/n:rootfile/@full-path', namespaces=ns)[0]
     cf = epubZip.read(cf_name)
 
-    return etree.fromstring(cf), cf_name
+    return etree.fromstring(cf, parser=_safe_parser), cf_name
 
 
 def create_new_metadata_backup(book,  custom_columns, export_language, translated_cover_name, lang_type=3):
diff --git a/cps/fb2.py b/cps/fb2.py
index 81eae579f..12ccbc1ca 100644
--- a/cps/fb2.py
+++ b/cps/fb2.py
@@ -20,6 +20,9 @@ from lxml import etree
 
 from .constants import BookMeta
 
+# Safe parser: disable entity resolution and network access to prevent XXE attacks
+_safe_parser = etree.XMLParser(resolve_entities=False, no_network=True)
+
 
 def get_fb2_info(tmp_file_path, original_file_extension):
 
@@ -29,7 +32,7 @@ def get_fb2_info(tmp_file_path, original_file_extension):
     }
 
     fb2_file = open(tmp_file_path, encoding="utf-8")
-    tree = etree.fromstring(fb2_file.read().encode())
+    tree = etree.fromstring(fb2_file.read().encode(), parser=_safe_parser)
 
     authors = tree.xpath('/fb:FictionBook/fb:description/fb:title-info/fb:author', namespaces=ns)
 
diff --git a/cps/services/goodreads_support.py b/cps/services/goodreads_support.py
index 06b218bf8..eec85b5b2 100644
--- a/cps/services/goodreads_support.py
+++ b/cps/services/goodreads_support.py
@@ -92,7 +92,7 @@ class my_GoodreadsRequest(GoodreadsRequest):
         if resp.status_code != 200:
             raise GoodreadsRequestException(resp.reason, self.path)
         if self.req_format == 'xml':
-            root = etree.fromstring(resp.content)
+            root = etree.fromstring(resp.content, parser=etree.XMLParser(resolve_entities=False, no_network=True))
             data_dict = etree_to_dict(root)
 
             return data_dict['GoodreadsResponse']