diff --git a/packages/models/src/models/LivechatRooms.ts b/packages/models/src/models/LivechatRooms.ts
index d388e7a39fd6e..eabcf3a50aa86 100644
--- a/packages/models/src/models/LivechatRooms.ts
+++ b/packages/models/src/models/LivechatRooms.ts
@@ -1330,8 +1330,9 @@ export class LivechatRoomsRaw extends BaseRaw<IOmnichannelRoom> implements ILive
 			query.tags = { $in: tags };
 		}
 		if (customFields && Object.keys(customFields).length) {
+			// Escape custom field values to prevent query failures and ReDoS
 			query.$and = Object.keys(customFields).map((key) => ({
-				[`livechatData.${key}`]: new RegExp(customFields[key], 'i'),
+				[`livechatData.${key}`]: new RegExp(escapeRegExp(customFields[key]), 'i'),
 			}));
 		}
 
@@ -1827,7 +1828,11 @@ export class LivechatRoomsRaw extends BaseRaw<IOmnichannelRoom> implements ILive
 		const query: Filter<IOmnichannelRoom> = {
 			't': 'l',
 			'v.token': visitorToken,
-			'$or': [{ 'email.thread': { $elemMatch: { $in: emailThread } } }, { 'email.thread': new RegExp(emailThread.join('|')) }],
+			'$or': [
+				{ 'email.thread': { $elemMatch: { $in: emailThread } } },
+				// Escape email thread IDs to prevent query failures and ReDoS
+				{ 'email.thread': new RegExp(emailThread.map((t) => escapeRegExp(t)).join('|')) },
+			],
 		};
 
 		return this.findOne(query, options);
@@ -1844,7 +1849,7 @@ export class LivechatRoomsRaw extends BaseRaw<IOmnichannelRoom> implements ILive
 			'v.token': visitorToken,
 			'$or': [
 				{ 'email.thread': { $elemMatch: { $in: emailThread } } },
-				{ 'email.thread': new RegExp(emailThread.map((t) => `"${t}"`).join('|')) },
+				{ 'email.thread': new RegExp(emailThread.map((t) => escapeRegExp(t)).join('|')) },
 			],
 			...(departmentId && { departmentId }),
 		};
@@ -1857,7 +1862,11 @@ export class LivechatRoomsRaw extends BaseRaw<IOmnichannelRoom> implements ILive
 			't': 'l',
 			'open': true,
 			'v.token': visitorToken,
-			'$or': [{ 'email.thread': { $elemMatch: { $in: emailThread } } }, { 'email.thread': new RegExp(emailThread.join('|')) }],
+			'$or': [
+				{ 'email.thread': { $elemMatch: { $in: emailThread } } },
+				// Escape email thread IDs to prevent query failures and ReDoS
+				{ 'email.thread': new RegExp(emailThread.map((t) => escapeRegExp(t)).join('|')) },
+			],
 		};
 
 		return this.findOne(query, options);
diff --git a/packages/models/src/models/ModerationReports.spec.ts b/packages/models/src/models/ModerationReports.spec.ts
new file mode 100644
index 0000000000000..59a497068dd33
--- /dev/null
+++ b/packages/models/src/models/ModerationReports.spec.ts
@@ -0,0 +1,66 @@
+import { ModerationReportsRaw } from './ModerationReports';
+
+describe('ModerationReportsRaw', () => {
+    it('should pass selector to $regex unchanged in findReportedMessagesByReportedUserId', async () => {
+        const mockCollection = {
+            find: jest.fn().mockReturnValue({ toArray: jest.fn().mockResolvedValue([]), _bsonType: 'Cursor' }),
+            countDocuments: jest.fn().mockResolvedValue(0),
+            collectionName: 'moderation_reports',
+            createIndexes: jest.fn().mockResolvedValue([]),
+        } as any;
+        const mockDb = {
+            collection: jest.fn().mockReturnValue(mockCollection),
+        } as any;
+
+        const moderationReportsRaw = new ModerationReportsRaw(mockDb);
+
+        await moderationReportsRaw.findReportedMessagesByReportedUserId('123', '.*', { offset: 0, count: 10 });
+
+        expect(mockCollection.find).toHaveBeenCalled();
+        const query = mockCollection.find.mock.calls[0][0];
+
+        expect(query['message.msg'].$regex).toBe('.*');
+    });
+
+    it('should pass selector to $regex unchanged in countMessageReportsInRange (getSearchQueryForSelector)', () => {
+        const mockCollection = {
+            countDocuments: jest.fn().mockResolvedValue(0),
+            collectionName: 'moderation_reports',
+            createIndexes: jest.fn().mockResolvedValue([]),
+        } as any;
+        const mockDb = {
+            collection: jest.fn().mockReturnValue(mockCollection),
+        } as any;
+
+        const moderationReportsRaw = new ModerationReportsRaw(mockDb);
+
+        moderationReportsRaw.countMessageReportsInRange(new Date(), new Date(), '.*');
+
+        expect(mockCollection.countDocuments).toHaveBeenCalled();
+        const query = mockCollection.countDocuments.mock.calls[0][0];
+
+        expect(query.$or[0]['message.msg'].$regex).toBe('.*');
+        expect(query.$or[1].description.$regex).toBe('.*');
+    });
+
+    it('should pass selector to $regex unchanged via getTotalUniqueReportedUsers (getSearchQueryForSelectorUsers)', async () => {
+        const mockCollection = {
+            aggregate: jest.fn().mockReturnValue({ toArray: jest.fn().mockResolvedValue([]) }),
+            collectionName: 'moderation_reports',
+            createIndexes: jest.fn().mockResolvedValue([]),
+        } as any;
+        const mockDb = {
+            collection: jest.fn().mockReturnValue(mockCollection),
+        } as any;
+
+        const moderationReportsRaw = new ModerationReportsRaw(mockDb);
+
+        await moderationReportsRaw.getTotalUniqueReportedUsers(new Date(), new Date(), '.*', false);
+
+        expect(mockCollection.aggregate).toHaveBeenCalled();
+        const pipeline = mockCollection.aggregate.mock.calls[0][0];
+        const matchStage = pipeline.find((stage: any) => stage.$match);
+
+        expect(matchStage.$match.$or[0]['reportedUser.username'].$regex).toBe('.*');
+    });
+});
diff --git a/packages/models/src/models/ModerationReports.ts b/packages/models/src/models/ModerationReports.ts
index 196b5161aef5c..0c19ffdf89853 100644
--- a/packages/models/src/models/ModerationReports.ts
+++ b/packages/models/src/models/ModerationReports.ts
@@ -239,11 +239,11 @@ export class ModerationReportsRaw extends BaseRaw<IModerationReport> implements
 
 		const fuzzyQuery = selector
 			? {
-					'message.msg': {
-						$regex: selector,
-						$options: 'i',
-					},
-				}
+				'message.msg': {
+					$regex: selector,
+					$options: 'i',
+				},
+			}
 			: {};
 
 		const params = {
diff --git a/packages/models/src/models/Sessions.spec.ts b/packages/models/src/models/Sessions.spec.ts
new file mode 100644
index 0000000000000..e15bb868fd0bf
--- /dev/null
+++ b/packages/models/src/models/Sessions.spec.ts
@@ -0,0 +1,50 @@
+import { SessionsRaw } from './Sessions';
+
+describe('SessionsRaw', () => {
+    it('should pass search parameter to $regex unchanged in aggregateSessionsByUserId', async () => {
+        const mockCollection = {
+            aggregate: jest.fn().mockReturnValue({ toArray: jest.fn().mockResolvedValue([]) }),
+            collectionName: 'sessions',
+            createIndexes: jest.fn().mockResolvedValue([]),
+        } as any;
+        const mockDb = {
+            collection: jest.fn().mockReturnValue(mockCollection),
+        } as any;
+
+        const sessionsRaw = new SessionsRaw(mockDb);
+
+        await sessionsRaw.aggregateSessionsByUserId({
+            uid: '123',
+            search: '.*', // raw regex that should not be escaped
+        });
+
+        expect(mockCollection.aggregate).toHaveBeenCalled();
+        const pipeline = mockCollection.aggregate.mock.calls[0][0];
+        const matchStage = pipeline.find((stage: any) => stage.$match);
+
+        expect(matchStage.$match.$and[0]).toEqual({ searchTerm: { $regex: '.*', $options: 'i' } });
+    });
+
+    it('should pass search parameter to $regex unchanged in aggregateSessionsAndPopulate', async () => {
+        const mockCollection = {
+            aggregate: jest.fn().mockReturnValue({ toArray: jest.fn().mockResolvedValue([]) }),
+            collectionName: 'sessions',
+            createIndexes: jest.fn().mockResolvedValue([]),
+        } as any;
+        const mockDb = {
+            collection: jest.fn().mockReturnValue(mockCollection),
+        } as any;
+
+        const sessionsRaw = new SessionsRaw(mockDb);
+
+        await sessionsRaw.aggregateSessionsAndPopulate({
+            search: 'a|b', // pipe should not be escaped
+        });
+
+        expect(mockCollection.aggregate).toHaveBeenCalled();
+        const pipeline = mockCollection.aggregate.mock.calls[0][0];
+        const matchStage = pipeline.find((stage: any) => stage.$match);
+
+        expect(matchStage.$match.$and[0]).toEqual({ searchTerm: { $regex: 'a|b', $options: 'i' } });
+    });
+});