diff --git a/docs/release-control/v6/internal/subsystems/monitoring.md b/docs/release-control/v6/internal/subsystems/monitoring.md
index 01450aad8..7020e83c4 100644
--- a/docs/release-control/v6/internal/subsystems/monitoring.md
+++ b/docs/release-control/v6/internal/subsystems/monitoring.md
@@ -291,6 +291,11 @@ canonical physical-disk model and the Proxmox polling runtime in
 `internal/monitoring/monitor_pve.go` must evaluate disk alerts only after that
 merged disk view exists, so controller-backed disks do not lose health and
 endurance coverage between collection and alerting.
+That same Proxmox monitoring boundary also owns checked response parsing for
+polymorphic numeric fields. Shared client parsers such as
+`pkg/proxmox/replication.go` must use the package's checked integer conversion
+helpers instead of direct casts, so malformed or oversized Proxmox values do
+not overflow into monitoring state.
 
 Backup polling and recovery guest identity assembly now derive workload node,
 name, and type context from canonical `ReadState` instead of from
diff --git a/pkg/proxmox/client.go b/pkg/proxmox/client.go
index 8d2df205a..f58458593 100644
--- a/pkg/proxmox/client.go
+++ b/pkg/proxmox/client.go
@@ -126,6 +126,13 @@ func floatToIntTrunc(v float64) (int, error) {
 	return int(v), nil
 }
 
+func floatToIntRounded(v float64) (int, error) {
+	if math.IsNaN(v) || math.IsInf(v, 0) {
+		return 0, fmt.Errorf("non-finite float %v cannot be converted to int", v)
+	}
+	return floatToIntTrunc(math.Round(v))
+}
+
 func looksLikeNumericLiteral(raw string) bool {
 	hasDigit := false
 	var prev rune
diff --git a/pkg/proxmox/replication.go b/pkg/proxmox/replication.go
index 919b6e1fd..f5e3babca 100644
--- a/pkg/proxmox/replication.go
+++ b/pkg/proxmox/replication.go
@@ -368,33 +368,39 @@ func intFromAny(value interface{}) (int, bool) {
 	case int32:
 		return int(v), true
 	case int64:
-		return int(v), true
+		parsed, err := int64ToInt(v)
+		return parsed, err == nil
 	case uint:
-		return int(v), true
+		parsed, err := uint64ToInt(uint64(v))
+		return parsed, err == nil
 	case uint8:
 		return int(v), true
 	case uint16:
 		return int(v), true
 	case uint32:
-		return int(v), true
+		parsed, err := uint64ToInt(uint64(v))
+		return parsed, err == nil
 	case uint64:
-		return int(v), true
+		parsed, err := uint64ToInt(v)
+		return parsed, err == nil
 	case float32:
-		if math.IsNaN(float64(v)) || math.IsInf(float64(v), 0) {
-			return 0, false
-		}
-		return int(math.Round(float64(v))), true
+		parsed, err := floatToIntRounded(float64(v))
+		return parsed, err == nil
 	case float64:
-		if math.IsNaN(v) || math.IsInf(v, 0) {
+		parsed, err := floatToIntRounded(v)
+		return parsed, err == nil
+	case json.Number:
+		s := strings.TrimSpace(v.String())
+		if i, err := v.Int64(); err == nil {
+			parsed, err := int64ToInt(i)
+			return parsed, err == nil
+		}
+		if !looksLikeFloatLiteral(s) {
 			return 0, false
 		}
-		return int(math.Round(v)), true
-	case json.Number:
-		if i, err := v.Int64(); err == nil {
-			return int(i), true
-		}
-		if f, err := v.Float64(); err == nil && !math.IsNaN(f) && !math.IsInf(f, 0) {
-			return int(math.Round(f)), true
+		if f, err := v.Float64(); err == nil {
+			parsed, err := floatToIntRounded(f)
+			return parsed, err == nil
 		}
 	case string:
 		s := strings.TrimSpace(v)
@@ -402,15 +408,24 @@ func intFromAny(value interface{}) (int, bool) {
 			return 0, false
 		}
 		if i, err := strconv.ParseInt(s, 10, 64); err == nil {
-			return int(i), true
+			parsed, err := int64ToInt(i)
+			return parsed, err == nil
 		}
-		if f, err := strconv.ParseFloat(s, 64); err == nil && !math.IsNaN(f) && !math.IsInf(f, 0) {
-			return int(math.Round(f)), true
+		if !looksLikeFloatLiteral(s) {
+			return 0, false
+		}
+		if f, err := strconv.ParseFloat(s, 64); err == nil {
+			parsed, err := floatToIntRounded(f)
+			return parsed, err == nil
 		}
 	}
 	return 0, false
 }
 
+func looksLikeFloatLiteral(s string) bool {
+	return strings.ContainsAny(s, ".eE")
+}
+
 func boolFromAny(value interface{}) (bool, bool) {
 	switch v := value.(type) {
 	case nil:
diff --git a/pkg/proxmox/replication_test.go b/pkg/proxmox/replication_test.go
index ec46f50c7..a4d570909 100644
--- a/pkg/proxmox/replication_test.go
+++ b/pkg/proxmox/replication_test.go
@@ -94,6 +94,7 @@ func TestIntFromAny(t *testing.T) {
 		{"uint16", uint16(65535), 65535, true},
 		{"uint32", uint32(42), 42, true},
 		{"uint64", uint64(42), 42, true},
+		{"uint64 overflow", ^uint64(0), 0, false},
 
 		// float types (rounded)
 		{"float32 integer", float32(42.0), 42, true},
@@ -107,16 +108,21 @@ func TestIntFromAny(t *testing.T) {
 		{"float64 NaN", math.NaN(), 0, false},
 		{"float64 +Inf", math.Inf(1), 0, false},
 		{"float64 -Inf", math.Inf(-1), 0, false},
+		{"float64 overflow", math.MaxFloat64, 0, false},
 
 		// json.Number
 		{"json.Number int", json.Number("42"), 42, true},
 		{"json.Number float", json.Number("42.6"), 43, true},
+		{"json.Number scientific float", json.Number("4.2e1"), 42, true},
+		{"json.Number oversized int", json.Number("9223372036854775808"), 0, false},
 		{"json.Number invalid", json.Number("abc"), 0, false},
 
 		// string
 		{"string int", "42", 42, true},
 		{"string negative", "-42", -42, true},
 		{"string float", "42.6", 43, true},
+		{"string scientific float", "4.2e1", 42, true},
+		{"string oversized int", "9223372036854775808", 0, false},
 		{"string empty", "", 0, false},
 		{"string whitespace", "  42  ", 42, true},
 		{"string invalid", "abc", 0, false},