diff --git a/tests/bugs/gh_7255_test.py b/tests/bugs/gh_7255_test.py
new file mode 100644
index 00000000..8ebea200
--- /dev/null
+++ b/tests/bugs/gh_7255_test.py
@@ -0,0 +1,144 @@
+#coding:utf-8
+
+"""
+ID:          issue-7255
+ISSUE:       https://github.com/FirebirdSQL/firebird/issues/7255
+TITLE:       READ COMMITTED READ CONSISTENCY mode is broken in Classic / SuperClassic on Linux (the newly created users are not visible to execute statement)
+DESCRIPTION:
+    Issue can be reproduced only if firebird.conf contains ReadConsistency = 1.
+    Problem will NOT appear if this parameter is set to 0 and we start transactions as 'READ COMMITTED READ CONSISTENCY'.
+    Because of that, it was decided to make copy of firebird.conf, read its content and remote any line with 'ReadConsistency'.
+    Then we add new line with ReadConsistency = 1 and OVERWRITE firebird.conf.
+    After this, we run ISQL with script similar to provided in the ticket.
+    Output must display name of new user and TIL of his transaction ('read committed read consistency') that is seen in procedure sp_main.
+    Finally, we revert changes in firebir.conf using its original copy.
+    All these actions are enclosed in the try/except/finally block.
+NOTES:
+    ### ACHTUNG ###
+    Test tries temporary to change content of firebird.conf. In any outcome, this content will be restored at final point.
+
+    Confirmed bug on 5.0.0.599, Classic. LINUX only.
+    Checked on 5.0.0.1397, 4.0.5.3098.
+
+    Command switch '--disable-db-cache' must be used if this test is running under 5.0.0.999 after some fresh FB with same ODS was tested.
+    Otherwise "internal Firebird consistency check (decompression overran buffer (179), file: sqz.cpp line: 293)" will raise.
+    Example:
+        /opt/distr/venv/bin/pytest --disable-db-cache -vv --tb=long --server qa_rundaily_FB50 tests/bugs/gh_7255_test.py
+"""
+import shutil
+import pytest
+import locale
+import re
+import time
+import platform
+from pathlib import Path
+from firebird.qa import *
+
+db = db_factory(async_write = True)
+act = python_act('db', substitutions = [('[ \t]+', ' ')])
+
+fbcfg_bak = temp_file('firebird.conf')
+p_read_consist_param = re.compile('ReadConsistency\\s*=\\s*(0|1)', re.IGNORECASE)
+TMP_USR_NAME = 'tmp$7255'
+
+@pytest.mark.skipif(platform.system() == 'Windows', reason='Reproduced on Linux only.')
+@pytest.mark.version('>=4.0.3')
+def test_1(act: Action, fbcfg_bak: Path, capsys):
+
+    if act.vars['server-arch'].lower() != 'classic':
+        pytest.skip('Can be reproduced only for Servermode = Classic.')
+
+    fbcfg_file = act.vars['home-dir'] / 'firebird.conf'
+    shutil.copy2(fbcfg_file, fbcfg_bak)
+
+    try:
+        fbcfg_ini = fbcfg_file.read_text(encoding='utf-8').splitlines()
+        fbcfg_new = []
+        for x in fbcfg_ini:
+            if p_read_consist_param.search(x):
+                pass
+            else:
+                fbcfg_new.append(x)
+
+        fbcfg_new.append('ReadConsistency = 1')
+        fbcfg_file.write_text('\n'.join(fbcfg_new), encoding='utf-8' )
+
+        test_sql = f"""
+            set list on;
+            commit;
+            SET KEEP_TRAN_PARAMS ON;
+            SET TRANSACTION READ COMMITTED READ CONSISTENCY;
+
+            create or alter user {TMP_USR_NAME} password '123';
+            commit;
+
+            set term ^;
+            create or alter procedure sp_main(
+                a_usr varchar(31), a_pwd varchar(31)
+            ) returns(
+                who varchar(50)
+               ,til varchar(50)
+            ) as
+            begin
+              for
+                  execute statement
+                         q'#select #'
+                      || q'#    a.mon$user as who #'
+                      || q'#    ,decode( #'
+                      || q'#        t.mon$isolation_mode #'
+                      || q'#        ,0, 'snapshot table stability' #'
+                      || q'#        ,1, 'concurrency (snapshot)' #'
+                      || q'#        ,2, 'read committed record version' #'
+                      || q'#        ,3, 'read committed no record version' #'
+                      || q'#        ,4, 'read committed read consistency' #'
+                      || q'#    ) as til #'
+                      || q'#from mon$attachments a #'
+                      || q'#join mon$transactions t on a.mon$attachment_id = t.mon$attachment_id #'
+                      || q'#where a.mon$attachment_id = current_connection and t.mon$state = 1 #'
+                  as user a_usr password a_pwd
+              into who, til
+              do
+                  suspend;
+            end
+            ^
+            set term ;^
+            commit;
+
+            grant execute on procedure sp_main to {TMP_USR_NAME};
+            commit;
+
+            -- wait 10 seconds and it will work
+
+            set term ^;
+            execute block returns(
+                who varchar(50)
+               ,til varchar(50)
+            ) as
+            begin
+                for
+                    execute statement ('select who, til from sp_main(:u, :p)') ( u := '{TMP_USR_NAME}', p := '123' )
+                into who, til
+                do
+                    suspend;
+            end
+            ^
+            set term ;^
+            commit;
+
+            drop user {TMP_USR_NAME};
+            commit;
+        """
+
+        act.isql(switches = ['-q'], input = test_sql, combine_output = True, io_enc = locale.getpreferredencoding())
+
+    except OSError as e:
+        print(e)
+    finally:
+        shutil.copy2(fbcfg_bak, act.vars['home-dir'] / 'firebird.conf')
+
+    act.expected_stdout = f"""
+        WHO {TMP_USR_NAME.upper()}
+        TIL read committed read consistency
+    """
+    # act.stdout = capsys.readouterr().out
+    assert act.clean_stdout == act.clean_expected_stdout