diff --git a/pkg/sql/exec_util.go b/pkg/sql/exec_util.go
index ceff7c4015a5..6287443b98dc 100644
--- a/pkg/sql/exec_util.go
+++ b/pkg/sql/exec_util.go
@@ -3197,6 +3197,10 @@ func (m *sessionDataMutator) SetExpectAndIgnoreNotVisibleColumnsInCopy(val bool)
 	m.data.ExpectAndIgnoreNotVisibleColumnsInCopy = val
 }
 
+func (m *sessionDataMutator) SetMultipleModificationsOfTable(val bool) {
+	m.data.MultipleModificationsOfTable = val
+}
+
 // Utility functions related to scrubbing sensitive information on SQL Stats.
 
 // quantizeCounts ensures that the Count field in the
diff --git a/pkg/sql/logictest/testdata/logic_test/with b/pkg/sql/logictest/testdata/logic_test/with
index 61ff01c7992b..53aeeabf9576 100644
--- a/pkg/sql/logictest/testdata/logic_test/with
+++ b/pkg/sql/logictest/testdata/logic_test/with
@@ -997,6 +997,31 @@ EXPERIMENTAL SCRUB TABLE t WITH OPTIONS INDEX ALL
 statement ok
 RESET CLUSTER SETTING sql.multiple_modifications_of_table.enabled
 
+# Multiple mutations can also be explicitly allowed with a session setting.
+statement ok
+SET enable_multiple_modifications_of_table = true
+
+# Multiple updates of different rows in the same table.
+query II rowsort
+WITH
+  u1 AS (UPDATE t SET j = j - 40 WHERE i < 20 RETURNING *),
+  u2 AS (UPDATE t SET j = j + 40 WHERE i >= 20 RETURNING *)
+TABLE u1 UNION ALL TABLE u2
+----
+2 60
+4 60
+6 60
+8 60
+20 440
+
+# Check for corruption.
+query TTTTTTTT
+EXPERIMENTAL SCRUB TABLE t WITH OPTIONS INDEX ALL
+----
+
+statement ok
+RESET enable_multiple_modifications_of_table
+
 # Tests with multiple mutations on the same table, modifying the same
 # rows. These testcases vary the type of mutation and the form. All should fail
 # with an error. When issue 70731 is fixed, some might no longer fail.
diff --git a/pkg/sql/opt/optbuilder/util.go b/pkg/sql/opt/optbuilder/util.go
index db6a3da42faa..08f27aca140b 100644
--- a/pkg/sql/opt/optbuilder/util.go
+++ b/pkg/sql/opt/optbuilder/util.go
@@ -27,6 +27,7 @@ import (
 	"github.com/cockroachdb/errors"
 )
 
+// TODO(michae2): Remove this when #70731 is fixed.
 var multipleModificationsOfTableEnabled = settings.RegisterBoolSetting(
 	settings.TenantWritable,
 	"sql.multiple_modifications_of_table.enabled",
@@ -493,7 +494,9 @@ func (b *Builder) checkMultipleMutations(tab cat.Table, simpleInsert bool) {
 	}
 	allSimpleInserts = allSimpleInserts && simpleInsert
 	b.areAllTableMutationsSimpleInserts[tab.ID()] = allSimpleInserts
-	if !allSimpleInserts && !multipleModificationsOfTableEnabled.Get(&b.evalCtx.Settings.SV) {
+	if !allSimpleInserts &&
+		!multipleModificationsOfTableEnabled.Get(&b.evalCtx.Settings.SV) &&
+		!b.evalCtx.SessionData().MultipleModificationsOfTable {
 		panic(pgerror.Newf(
 			pgcode.FeatureNotSupported,
 			"multiple modification subqueries of the same table %q are not supported unless "+
diff --git a/pkg/sql/sessiondatapb/local_only_session_data.proto b/pkg/sql/sessiondatapb/local_only_session_data.proto
index a107c7ec71d5..156d6c357aa9 100644
--- a/pkg/sql/sessiondatapb/local_only_session_data.proto
+++ b/pkg/sql/sessiondatapb/local_only_session_data.proto
@@ -246,6 +246,10 @@ message LocalOnlySessionData {
   // (with no column name specifiers) to expect and ignore not visible column
   // fields.
   bool expect_and_ignore_not_visible_columns_in_copy = 67;
+  // MultipleModificationsOfTable allows statements containing multiple INSERT
+  // ON CONFLICT, UPSERT, UPDATE, or DELETE subqueries modifying the same table,
+  // at the risk of data corruption if the same row is modified multiple times.
+  bool multiple_modifications_of_table = 68;
 
   ///////////////////////////////////////////////////////////////////////////
   // WARNING: consider whether a session parameter you're adding needs to  //
diff --git a/pkg/sql/vars.go b/pkg/sql/vars.go
index 242dabf510c9..04eadb9127fa 100644
--- a/pkg/sql/vars.go
+++ b/pkg/sql/vars.go
@@ -2049,6 +2049,24 @@ var varGen = map[string]sessionVar{
 		},
 		GlobalDefault: globalFalse,
 	},
+
+	// TODO(michae2): Remove this when #70731 is fixed.
+	// CockroachDB extension.
+	`enable_multiple_modifications_of_table`: {
+		GetStringVal: makePostgresBoolGetStringValFn(`enable_multiple_modifications_of_table`),
+		Set: func(_ context.Context, m sessionDataMutator, s string) error {
+			b, err := paramparse.ParseBoolVar("enable_multiple_modifications_of_table", s)
+			if err != nil {
+				return err
+			}
+			m.SetMultipleModificationsOfTable(b)
+			return nil
+		},
+		Get: func(evalCtx *extendedEvalContext) (string, error) {
+			return formatBoolAsPostgresSetting(evalCtx.SessionData().MultipleModificationsOfTable), nil
+		},
+		GlobalDefault: globalFalse,
+	},
 }
 
 const compatErrMsg = "this parameter is currently recognized only for compatibility and has no effect in CockroachDB."