diff -r 11872e3b4cdb Lib/gettext.py
--- a/Lib/gettext.py	Mon Oct 06 17:51:53 2014 +0200
+++ b/Lib/gettext.py	Mon Oct 06 14:59:02 2014 -0400
@@ -225,6 +225,9 @@
     LE_MAGIC = 0x950412de
     BE_MAGIC = 0xde120495
 
+    # Acceptable .mo versions
+    VERSIONS = (0, 1)
+
     def _parse(self, fp):
         """Override this method to support alternative .mo formats."""
         unpack = struct.unpack
@@ -245,6 +248,10 @@
             ii = '>II'
         else:
             raise OSError(0, 'Bad magic number', filename)
+
+        if not version in self.VERSIONS:
+            raise OSError(0, 'Bad version number 5', filename)
+
         # Now put all messages from the .mo file buffer into the catalog
         # dictionary.
         for i in range(0, msgcount):
diff -r 11872e3b4cdb Lib/test/test_gettext.py
--- a/Lib/test/test_gettext.py	Mon Oct 06 17:51:53 2014 +0200
+++ b/Lib/test/test_gettext.py	Mon Oct 06 14:59:02 2014 -0400
@@ -33,6 +33,26 @@
 ciBUQUgKdHJnZ3JrZyB6cmZmbnRyIHBuZ255YnQgeXZvZW5lbC4AYmFjb24Ad2luayB3aW5rAA==
 '''
 
+GNU_MO_DATA_BAD_VERSION = b'''\
+3hIElQAAAAUGAAAAHAAAAEwAAAALAAAAfAAAAAAAAACoAAAAFQAAAKkAAAAjAAAAvwAAAKEAAADj
+AAAABwAAAIUBAAALAAAAjQEAAEUBAACZAQAAFgAAAN8CAAAeAAAA9gIAAKEAAAAVAwAABQAAALcD
+AAAJAAAAvQMAAAEAAAADAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAEAAAABQAAAAYAAAACAAAAAFJh
+eW1vbmQgTHV4dXJ5IFlhY2gtdABUaGVyZSBpcyAlcyBmaWxlAFRoZXJlIGFyZSAlcyBmaWxlcwBU
+aGlzIG1vZHVsZSBwcm92aWRlcyBpbnRlcm5hdGlvbmFsaXphdGlvbiBhbmQgbG9jYWxpemF0aW9u
+CnN1cHBvcnQgZm9yIHlvdXIgUHl0aG9uIHByb2dyYW1zIGJ5IHByb3ZpZGluZyBhbiBpbnRlcmZh
+Y2UgdG8gdGhlIEdOVQpnZXR0ZXh0IG1lc3NhZ2UgY2F0YWxvZyBsaWJyYXJ5LgBtdWxsdXNrAG51
+ZGdlIG51ZGdlAFByb2plY3QtSWQtVmVyc2lvbjogMi4wClBPLVJldmlzaW9uLURhdGU6IDIwMDAt
+MDgtMjkgMTI6MTktMDQ6MDAKTGFzdC1UcmFuc2xhdG9yOiBKLiBEYXZpZCBJYsOhw7FleiA8ai1k
+YXZpZEBub29zLmZyPgpMYW5ndWFnZS1UZWFtOiBYWCA8cHl0aG9uLWRldkBweXRob24ub3JnPgpN
+SU1FLVZlcnNpb246IDEuMApDb250ZW50LVR5cGU6IHRleHQvcGxhaW47IGNoYXJzZXQ9aXNvLTg4
+NTktMQpDb250ZW50LVRyYW5zZmVyLUVuY29kaW5nOiBub25lCkdlbmVyYXRlZC1CeTogcHlnZXR0
+ZXh0LnB5IDEuMQpQbHVyYWwtRm9ybXM6IG5wbHVyYWxzPTI7IHBsdXJhbD1uIT0xOwoAVGhyb2F0
+d29iYmxlciBNYW5ncm92ZQBIYXkgJXMgZmljaGVybwBIYXkgJXMgZmljaGVyb3MAR3V2ZiB6YnFo
+eXIgY2ViaXZxcmYgdmFncmVhbmd2YmFueXZtbmd2YmEgbmFxIHlicG55dm1uZ3ZiYQpmaGNjYmVn
+IHNiZSBsYmhlIENsZ3ViYSBjZWJ0ZW56ZiBvbCBjZWJpdnF2YXQgbmEgdmFncmVzbnByIGdiIGd1
+ciBUQUgKdHJnZ3JrZyB6cmZmbnRyIHBuZ255YnQgeXZvZW5lbC4AYmFjb24Ad2luayB3aW5rAA=='
+'''
+
 UMO_DATA = b'''\
 3hIElQAAAAACAAAAHAAAACwAAAAFAAAAPAAAAAAAAABQAAAABAAAAFEAAAAPAQAAVgAAAAQAAABm
 AQAAAQAAAAIAAAAAAAAAAAAAAAAAAAAAYWLDngBQcm9qZWN0LUlkLVZlcnNpb246IDIuMApQTy1S
@@ -56,6 +76,7 @@
 
 LOCALEDIR = os.path.join('xx', 'LC_MESSAGES')
 MOFILE = os.path.join(LOCALEDIR, 'gettext.mo')
+MOFILE_BAD_VERSION = os.path.join(LOCALEDIR, 'gettext_bad_version.mo')
 UMOFILE = os.path.join(LOCALEDIR, 'ugettext.mo')
 MMOFILE = os.path.join(LOCALEDIR, 'metadata.mo')
 
@@ -66,6 +87,8 @@
             os.makedirs(LOCALEDIR)
         with open(MOFILE, 'wb') as fp:
             fp.write(base64.decodebytes(GNU_MO_DATA))
+        with open(MOFILE_BAD_VERSION, 'wb') as fp:
+            fp.write(base64.decodebytes(GNU_MO_DATA_BAD_VERSION))
         with open(UMOFILE, 'wb') as fp:
             fp.write(base64.decodebytes(UMO_DATA))
         with open(MMOFILE, 'wb') as fp:
@@ -166,6 +189,16 @@
     def test_textdomain(self):
         self.assertEqual(gettext.textdomain(), 'gettext')
 
+    def test_bad_version(self):
+        with open(MOFILE_BAD_VERSION, 'rb') as fp:
+            with self.assertRaises(OSError) as cm:
+                gettext.GNUTranslations(fp)
+
+            exception = cm.exception
+            self.assertEqual(exception.errno, 0)
+            self.assertEqual(exception.strerror, "Bad version number 5")
+            self.assertEqual(exception.filename, MOFILE_BAD_VERSION)
+
     def test_some_translations(self):
         eq = self.assertEqual
         # test some translations