diff --git a/data/txt/sha256sums.txt b/data/txt/sha256sums.txt
index cfd816895..ad82c9835 100644
--- a/data/txt/sha256sums.txt
+++ b/data/txt/sha256sums.txt
@@ -170,7 +170,7 @@ ac44a343947162532dbf17bd1f9ab424f8008f677367c5ad3f9f7b715a679818  lib/core/agent
 86a9cb82c7e7beb4730264dae20bf3b7cd87c0dcaee587367362cf319f7bb079  lib/core/bigarray.py
 f6062e324fdeaacf9df0a289fc3f12f755143e3876a70cb65b38aa2e690f73c1  lib/core/common.py
 11c748cc96ea2bc507bc6c1930a17fe4bc6fdd2dd2a80430df971cb21428eb00  lib/core/compat.py
-39ea62d4224be860befeffb3843c150f2343b64555ad8c438a400222056f6cc0  lib/core/convert.py
+8ce42a336f9acc1a10874ee7be4492ae30fb08b79caea20512d109670a2fa159  lib/core/convert.py
 ae500647c4074681749735a4f3b17b7eca44868dd3f39f9cab0a575888ba04a1  lib/core/data.py
 b22decc8389c94a13f1adf07eb343cf3b2aae3fb3909fd4107e24bbede7c7deb  lib/core/datatype.py
 253309dc355ae27cd275e7de5a068e7e22feba603c4fe3429e2b69f8a51c0d13  lib/core/decorators.py
@@ -190,7 +190,7 @@ c4bfb493a03caf84dd362aec7c248097841de804b7413d0e1ecb8a90c8550bc0  lib/core/readl
 d1bd70c1a55858495c727fbec91e30af267459c8f64d50fabf9e4ee2c007e920  lib/core/replication.py
 1d0f80b0193ac5204527bfab4bde1a7aee0f693fd008e86b4b29f606d1ef94f3  lib/core/revision.py
 d2eb8e4b05ac93551272b3d4abfaf5b9f2d3ac92499a7704c16ed0b4f200db38  lib/core/session.py
-9fd2f4141bce8cfa5b0e10d7391c12b46fa5a7d574c548a5d75597ff6df48bf0  lib/core/settings.py
+133e0f45cb7f03ea2322235892d6dff38302ddf65c0a7940976e6f54d65147b4  lib/core/settings.py
 1c5eab9494eb969bc9ce118a2ea6954690c6851cbe54c18373c723b99734bf09  lib/core/shell.py
 4eea6dcf023e41e3c64b210cb5c2efc7ca893b727f5e49d9c924f076bb224053  lib/core/subprocessng.py
 cdd352e1331c6b535e780f6edea79465cb55af53aa2114dcea0e8bf382e56d1a  lib/core/target.py
@@ -393,7 +393,7 @@ a1cf9a8cd5e263d1e48dc8b5281febaf868ee91f1e0587dee915949fdb6da1ea  plugins/dbms/m
 84d9f336ff3d75a1127c7f5ccda7bff6dac947d7d8bbeee2014e8a29b984a98d  plugins/dbms/monetdb/takeover.py
 545fbbb386ab7819261a3917d0f016d723dbced8e065945ba60271a73544c459  plugins/dbms/mssqlserver/connector.py
 2895d14ead30d7ee4e1fdb29a8d1d059493ad60490ed2e9ff6cb9680257554cd  plugins/dbms/mssqlserver/enumeration.py
-89cbc49cd9113e9ba91be090f79c0384089d1bfed785ac8ee5b07f84309c74cb  plugins/dbms/mssqlserver/filesystem.py
+5f8789cca87732612044fa1b952eceb52c0a354d70dc31fb9fe966ce796f89b7  plugins/dbms/mssqlserver/filesystem.py
 87a35cadd3fe4987f548f498c442f748cf1f37650fd1dcd8decd1455a90d675c  plugins/dbms/mssqlserver/fingerprint.py
 784d6065921a8efbba970864a2cb2e0ef1dd1fcea7181cfc3f737bbfa18f0574  plugins/dbms/mssqlserver/__init__.py
 79a887b5a2449bb086805560ff0ec2a2304dd142f47450ae9c2f88cf8bda9ac9  plugins/dbms/mssqlserver/syntax.py
diff --git a/lib/core/convert.py b/lib/core/convert.py
index 352b46ffa..015491004 100644
--- a/lib/core/convert.py
+++ b/lib/core/convert.py
@@ -138,29 +138,6 @@ def dejsonize(data):
 
     return json.loads(data)
 
-def rot13(data):
-    """
-    Returns ROT13 encoded/decoded text
-
-    >>> rot13('foobar was here!!')
-    'sbbone jnf urer!!'
-    >>> rot13('sbbone jnf urer!!')
-    'foobar was here!!'
-    >>> rot13(b'foobar was here!!')
-    'sbbone jnf urer!!'
-    """
-
-    retVal = ""
-    alphabit = "abcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZABCDEFGHIJKLMNOPQRSTUVWXYZ"
-
-    if isinstance(data, six.binary_type):
-        data = getText(data)
-
-    for char in data:
-        retVal += alphabit[alphabit.index(char) + 13] if char in alphabit else char
-
-    return retVal
-
 def decodeHex(value, binary=True):
     """
     Returns a decoded representation of the provided hexadecimal value
diff --git a/lib/core/settings.py b/lib/core/settings.py
index bccba1c26..f5aea82a1 100644
--- a/lib/core/settings.py
+++ b/lib/core/settings.py
@@ -19,7 +19,7 @@ from lib.core.enums import OS
 from thirdparty import six
 
 # sqlmap version (<major>.<minor>.<month>.<monthly commit>)
-VERSION = "1.9.12.51"
+VERSION = "1.9.12.52"
 TYPE = "dev" if VERSION.count('.') > 2 and VERSION.split('.')[-1] != '0' else "stable"
 TYPE_COLORS = {"dev": 33, "stable": 90, "pip": 34}
 VERSION_STRING = "sqlmap/%s#%s" % ('.'.join(VERSION.split('.')[:-1]) if VERSION.count('.') > 2 and VERSION.split('.')[-1] == '0' else VERSION, TYPE)
diff --git a/plugins/dbms/mssqlserver/filesystem.py b/plugins/dbms/mssqlserver/filesystem.py
index 33cfb077c..8da7cf7ab 100644
--- a/plugins/dbms/mssqlserver/filesystem.py
+++ b/plugins/dbms/mssqlserver/filesystem.py
@@ -5,6 +5,7 @@ Copyright (c) 2006-2025 sqlmap developers (https://sqlmap.org)
 See the file 'LICENSE' for copying permission
 """
 
+import codecs
 import ntpath
 import os
 
@@ -18,7 +19,6 @@ from lib.core.common import readInput
 from lib.core.compat import xrange
 from lib.core.convert import encodeBase64
 from lib.core.convert import encodeHex
-from lib.core.convert import rot13
 from lib.core.data import conf
 from lib.core.data import kb
 from lib.core.data import logger
@@ -334,7 +334,7 @@ class Filesystem(GenericFilesystem):
         Raq Shapgvba"""
 
         # NOTE: https://github.com/sqlmapproject/sqlmap/issues/5581
-        vbs = rot13(vbs)
+        vbs = codecs.decode(vbs, "rot13")
         vbs = vbs.replace("    ", "")
         encodedFileContent = encodeBase64(localFileContent, binary=False)