diff --git a/api/schemas/schemas.py b/api/schemas/schemas.py
index f873d32a8..973dce8f1 100644
--- a/api/schemas/schemas.py
+++ b/api/schemas/schemas.py
@@ -3,12 +3,13 @@ from typing import Optional, List, Union, Literal
 
 from pydantic import Field, EmailStr, HttpUrl, SecretStr, AnyHttpUrl
 from pydantic import field_validator, model_validator, computed_field
+from pydantic import AfterValidator
 from pydantic.functional_validators import BeforeValidator
 
 from chalicelib.utils.TimeUTC import TimeUTC
 from .overrides import BaseModel, Enum, ORUnion
 from .transformers_validators import transform_email, remove_whitespace, remove_duplicate_values, single_to_list, \
-    force_is_event, NAME_PATTERN, int_to_string, check_alphanumeric
+    force_is_event, NAME_PATTERN, int_to_string, check_alphanumeric, check_regex
 
 
 class _GRecaptcha(BaseModel):
@@ -537,7 +538,7 @@ class GraphqlFilterType(str, Enum):
 class RequestGraphqlFilterSchema(BaseModel):
     type: Union[FetchFilterType, GraphqlFilterType] = Field(...)
     value: List[Union[int, str]] = Field(...)
-    operator: Union[SearchEventOperator, MathOperator] = Field(...)
+    operator: Annotated[Union[SearchEventOperator, MathOperator], AfterValidator(check_regex)] = Field(...)
 
     @model_validator(mode="before")
     @classmethod
@@ -612,6 +613,13 @@ class PropertyFilterSchema(BaseModel):
             self.name = self.name.value
         return self
 
+    @model_validator(mode='after')
+    def _check_regex_value(self):
+        if self.operator == SearchEventOperator.PATTERN:
+            for v in self.value:
+                check_regex(v)
+        return self
+
 
 class EventPropertiesSchema(BaseModel):
     operator: Literal["and", "or"] = Field(...)
@@ -657,6 +665,13 @@ class SessionSearchEventSchema(BaseModel):
                 f"operator:{self.operator} is only available for event-type: {EventType.CLICK}"
         return self
 
+    @model_validator(mode='after')
+    def _check_regex_value(self):
+        if self.operator == SearchEventOperator.PATTERN:
+            for v in self.value:
+                check_regex(v)
+        return self
+
 
 class SessionSearchFilterSchema(BaseModel):
     is_event: Literal[False] = False
@@ -714,6 +729,13 @@ class SessionSearchFilterSchema(BaseModel):
 
         return self
 
+    @model_validator(mode='after')
+    def _check_regex_value(self):
+        if self.operator == SearchEventOperator.PATTERN:
+            for v in self.value:
+                check_regex(v)
+        return self
+
 
 class _PaginatedSchema(BaseModel):
     limit: int = Field(default=200, gt=0, le=200)
@@ -880,6 +902,13 @@ class PathAnalysisSubFilterSchema(BaseModel):
         values["isEvent"] = True
         return values
 
+    @model_validator(mode='after')
+    def _check_regex_value(self):
+        if self.operator == SearchEventOperator.PATTERN:
+            for v in self.value:
+                check_regex(v)
+        return self
+
 
 class _ProductAnalyticsFilter(BaseModel):
     is_event: Literal[False] = False
@@ -890,6 +919,13 @@ class _ProductAnalyticsFilter(BaseModel):
 
     _remove_duplicate_values = field_validator('value', mode='before')(remove_duplicate_values)
 
+    @model_validator(mode='after')
+    def _check_regex_value(self):
+        if self.operator == SearchEventOperator.PATTERN:
+            for v in self.value:
+                check_regex(v)
+        return self
+
 
 class _ProductAnalyticsEventFilter(BaseModel):
     is_event: Literal[True] = True
@@ -900,6 +936,13 @@ class _ProductAnalyticsEventFilter(BaseModel):
 
     _remove_duplicate_values = field_validator('value', mode='before')(remove_duplicate_values)
 
+    @model_validator(mode='after')
+    def _check_regex_value(self):
+        if self.operator == SearchEventOperator.PATTERN:
+            for v in self.value:
+                check_regex(v)
+        return self
+
 
 # this type is created to allow mixing events&filters and specifying a discriminator for PathAnalysis series filter
 ProductAnalyticsFilter = Annotated[Union[_ProductAnalyticsFilter, _ProductAnalyticsEventFilter],
@@ -1344,6 +1387,13 @@ class LiveSessionSearchFilterSchema(BaseModel):
             assert len(self.source) > 0, "source should not be empty for METADATA type"
         return self
 
+    @model_validator(mode='after')
+    def _check_regex_value(self):
+        if self.operator == SearchEventOperator.PATTERN:
+            for v in self.value:
+                check_regex(v)
+        return self
+
 
 class LiveSessionsSearchPayloadSchema(_PaginatedSchema):
     filters: List[LiveSessionSearchFilterSchema] = Field([])
diff --git a/api/schemas/transformers_validators.py b/api/schemas/transformers_validators.py
index 106f8747c..90d88aead 100644
--- a/api/schemas/transformers_validators.py
+++ b/api/schemas/transformers_validators.py
@@ -1,3 +1,4 @@
+import re
 from typing import Union, Any, Type
 
 from pydantic import ValidationInfo
@@ -57,3 +58,17 @@ def check_alphanumeric(v: str, info: ValidationInfo) -> str:
         is_alphanumeric = v.replace(' ', '').isalnum()
         assert is_alphanumeric, f'{info.field_name} must be alphanumeric'
     return v
+
+
+def check_regex(v: str) -> str:
+    assert v is not None, "Regex is null"
+    assert isinstance(v, str), "Regex value must be a string"
+    assert len(v) > 0, "Regex is empty"
+    is_valid = None
+    try:
+        re.compile(v)
+    except re.error as exc:
+        is_valid = f"Invalid regex: {exc} (at position {exc.pos})"
+
+    assert is_valid is None, is_valid
+    return v