diff --git a/spec/PostgresStorageAdapter.spec.js b/spec/PostgresStorageAdapter.spec.js
index aa5e692fe4..9c0c5c49ce 100644
--- a/spec/PostgresStorageAdapter.spec.js
+++ b/spec/PostgresStorageAdapter.spec.js
@@ -589,3 +589,213 @@ describe_only_db('postgres')('PostgresStorageAdapter shutdown', () => {
     expect(adapter._client.$pool.ending).toEqual(true);
   });
 });
+
+describe_only_db('postgres')('PostgresStorageAdapter Increment JSON key escaping', () => {
+  const request = require('../lib/request');
+  const headers = {
+    'Content-Type': 'application/json',
+    'X-Parse-Application-Id': 'test',
+    'X-Parse-REST-API-Key': 'rest',
+  };
+
+  it('does not inject additional JSONB keys via double-quote in sub-key name', async () => {
+    const obj = new Parse.Object('IncrementTest');
+    obj.set('metadata', { score: 100, isAdmin: 0 });
+    await obj.save();
+
+    // Advisory payload: sub-key `":0,"isAdmin` produces JSON `{"":0,"isAdmin":amount}`
+    // which would inject/overwrite the `isAdmin` key via JSONB `||` merge
+    await request({
+      method: 'PUT',
+      url: `http://localhost:8378/1/classes/IncrementTest/${obj.id}`,
+      headers,
+      body: JSON.stringify({
+        'metadata.":0,"isAdmin': { __op: 'Increment', amount: 1 },
+      }),
+    }).catch(() => {});
+
+    const verify = await new Parse.Query('IncrementTest').get(obj.id);
+    // isAdmin must NOT have been changed by the injection
+    expect(verify.get('metadata').isAdmin).toBe(0);
+    // score must remain unchanged
+    expect(verify.get('metadata').score).toBe(100);
+    // No spurious empty-string key should exist
+    expect(verify.get('metadata')['']).toBeUndefined();
+  });
+
+  it('does not overwrite existing JSONB keys via crafted sub-key injection', async () => {
+    const obj = new Parse.Object('IncrementTest');
+    obj.set('metadata', { balance: 500 });
+    await obj.save();
+
+    // Attempt to overwrite `balance` with 0 via injection, then set injected key to amount
+    await request({
+      method: 'PUT',
+      url: `http://localhost:8378/1/classes/IncrementTest/${obj.id}`,
+      headers,
+      body: JSON.stringify({
+        'metadata.":0,"balance': { __op: 'Increment', amount: 0 },
+      }),
+    }).catch(() => {});
+
+    const verify = await new Parse.Query('IncrementTest').get(obj.id);
+    // balance must NOT have been overwritten
+    expect(verify.get('metadata').balance).toBe(500);
+  });
+
+  it('does not escalate write access beyond what CLP already grants', async () => {
+    // A user with write CLP can already overwrite any sub-key of an Object field
+    // directly, so the JSON key injection does not grant additional capabilities.
+    const schema = new Parse.Schema('IncrementCLPTest');
+    schema.addObject('metadata');
+    schema.setCLP({
+      find: { '*': true },
+      get: { '*': true },
+      create: { '*': true },
+      update: { '*': true },
+      addField: {},
+    });
+    await schema.save();
+
+    const obj = new Parse.Object('IncrementCLPTest');
+    obj.set('metadata', { score: 100, isAdmin: 0 });
+    await obj.save();
+
+    // A user with write CLP can already directly overwrite any sub-key
+    const directResponse = await request({
+      method: 'PUT',
+      url: `http://localhost:8378/1/classes/IncrementCLPTest/${obj.id}`,
+      headers,
+      body: JSON.stringify({
+        'metadata.isAdmin': { __op: 'Increment', amount: 1 },
+      }),
+    });
+    expect(directResponse.status).toBe(200);
+
+    const afterDirect = await new Parse.Query('IncrementCLPTest').get(obj.id);
+    // Direct Increment already overwrites the key — no injection needed
+    expect(afterDirect.get('metadata').isAdmin).toBe(1);
+  });
+
+  it('does not bypass protectedFields — injection has same access as direct write', async () => {
+    const user = await Parse.User.signUp('protuser', 'password123');
+
+    const schema = new Parse.Schema('IncrementProtectedTest');
+    schema.addObject('metadata');
+    schema.setCLP({
+      find: { '*': true },
+      get: { '*': true },
+      create: { '*': true },
+      update: { '*': true },
+      addField: {},
+      protectedFields: { '*': ['metadata'] },
+    });
+    await schema.save();
+
+    const obj = new Parse.Object('IncrementProtectedTest');
+    obj.set('metadata', { score: 100, isAdmin: 0 });
+    await obj.save(null, { useMasterKey: true });
+
+    // Injection attempt on a protected field
+    await request({
+      method: 'PUT',
+      url: `http://localhost:8378/1/classes/IncrementProtectedTest/${obj.id}`,
+      headers: {
+        ...headers,
+        'X-Parse-Session-Token': user.getSessionToken(),
+      },
+      body: JSON.stringify({
+        'metadata.":0,"isAdmin': { __op: 'Increment', amount: 1 },
+      }),
+    }).catch(() => {});
+
+    // Direct write to same protected field
+    await request({
+      method: 'PUT',
+      url: `http://localhost:8378/1/classes/IncrementProtectedTest/${obj.id}`,
+      headers: {
+        ...headers,
+        'X-Parse-Session-Token': user.getSessionToken(),
+      },
+      body: JSON.stringify({
+        'metadata.isAdmin': { __op: 'Increment', amount: 1 },
+      }),
+    });
+
+    // Both succeed — protectedFields controls read access, not write access.
+    // The injection has the same access as a direct write.
+    const verify = await new Parse.Query('IncrementProtectedTest').get(obj.id, { useMasterKey: true });
+
+    // Direct write succeeded (protectedFields doesn't block writes)
+    expect(verify.get('metadata').isAdmin).toBeGreaterThanOrEqual(1);
+
+    // Verify the field is indeed read-protected for the user
+    const userResult = await new Parse.Query('IncrementProtectedTest').get(obj.id, { sessionToken: user.getSessionToken() });
+    expect(userResult.get('metadata')).toBeUndefined();
+  });
+
+  it('rejects injection when user lacks write CLP', async () => {
+    const user = await Parse.User.signUp('testuser', 'password123');
+
+    const schema = new Parse.Schema('IncrementNoCLPTest');
+    schema.addObject('metadata');
+    schema.setCLP({
+      find: { '*': true },
+      get: { '*': true },
+      create: { '*': true },
+      update: {},
+      addField: {},
+    });
+    await schema.save();
+
+    const obj = new Parse.Object('IncrementNoCLPTest');
+    obj.set('metadata', { score: 100, isAdmin: 0 });
+    await obj.save(null, { useMasterKey: true });
+
+    // Without write CLP, the injection attempt is rejected
+    await request({
+      method: 'PUT',
+      url: `http://localhost:8378/1/classes/IncrementNoCLPTest/${obj.id}`,
+      headers: {
+        ...headers,
+        'X-Parse-Session-Token': user.getSessionToken(),
+      },
+      body: JSON.stringify({
+        'metadata.":0,"isAdmin': { __op: 'Increment', amount: 1 },
+      }),
+    }).catch(() => {});
+
+    const verify = await new Parse.Query('IncrementNoCLPTest').get(obj.id);
+    // isAdmin unchanged — CLP blocked the write
+    expect(verify.get('metadata').isAdmin).toBe(0);
+  });
+
+  it('rejects injection when user lacks write access via ACL', async () => {
+    const owner = await Parse.User.signUp('owner', 'password123');
+    const attacker = await Parse.User.signUp('attacker', 'password456');
+
+    const obj = new Parse.Object('IncrementACLTest');
+    obj.set('metadata', { score: 100, isAdmin: 0 });
+    const acl = new Parse.ACL(owner);
+    acl.setPublicReadAccess(true);
+    obj.setACL(acl);
+    await obj.save(null, { useMasterKey: true });
+
+    // Attacker has public read but not write — injection attempt should fail
+    await request({
+      method: 'PUT',
+      url: `http://localhost:8378/1/classes/IncrementACLTest/${obj.id}`,
+      headers: {
+        ...headers,
+        'X-Parse-Session-Token': attacker.getSessionToken(),
+      },
+      body: JSON.stringify({
+        'metadata.":0,"isAdmin': { __op: 'Increment', amount: 1 },
+      }),
+    }).catch(() => {});
+
+    const verify = await new Parse.Query('IncrementACLTest').get(obj.id);
+    // isAdmin unchanged — ACL blocked the write
+    expect(verify.get('metadata').isAdmin).toBe(0);
+  });
+});
diff --git a/spec/vulnerabilities.spec.js b/spec/vulnerabilities.spec.js
index dc73888a67..6c734f308b 100644
--- a/spec/vulnerabilities.spec.js
+++ b/spec/vulnerabilities.spec.js
@@ -1615,25 +1615,23 @@ describe('(GHSA-gqpp-xgvh-9h7h) SQL Injection via dot-notation sub-key name in I
     }).catch(() => {});
     const elapsed = Date.now() - start;
 
-    // Double quotes break JSON structure inside the CONCAT, producing invalid JSONB.
-    // This causes a database error, NOT SQL injection. If injection succeeded,
-    // the query would take >= 3 seconds due to pg_sleep.
+    // Double quotes are escaped in the JSON context, producing a harmless literal key
+    // name. No SQL injection occurs. If injection succeeded, the query would take
+    // >= 3 seconds due to pg_sleep.
     expect(elapsed).toBeLessThan(3000);
-    // Invalid JSONB cast fails the UPDATE, so the row is not modified
     const verify = await new Parse.Query('SubKeyTest').get(obj.id);
-    expect(verify.get('stats')).toEqual({ counter: 0 });
+    // Original counter is untouched
+    expect(verify.get('stats').counter).toBe(0);
   });
 
-  it_only_db('postgres')('does not execute injected SQL via double quote crafted as valid JSONB in sub-key name', async () => {
+  it_only_db('postgres')('does not inject additional JSONB keys via double quote crafted as valid JSONB in sub-key name', async () => {
     const obj = new Parse.Object('SubKeyTest');
     obj.set('stats', { counter: 0 });
     await obj.save();
 
-    // This payload uses double quotes to craft a sub-key that produces valid JSONB
-    // (e.g. '{"x":0,"evil":1}') instead of breaking JSON structure. Even so, both
-    // interpolation sites are inside single-quoted SQL strings, so double quotes
-    // cannot escape the SQL context — no arbitrary SQL execution is possible.
-    const start = Date.now();
+    // This payload attempts to craft a sub-key that produces valid JSONB with
+    // injected keys (e.g. '{"x":0,"evil":1}'). Double quotes are escaped in the
+    // JSON context, so the payload becomes a harmless literal key name instead.
     await request({
       method: 'PUT',
       url: `http://localhost:8378/1/classes/SubKeyTest/${obj.id}`,
@@ -1642,13 +1640,12 @@ describe('(GHSA-gqpp-xgvh-9h7h) SQL Injection via dot-notation sub-key name in I
         'stats.x":0,"pg_sleep(3)': { __op: 'Increment', amount: 1 },
       }),
     }).catch(() => {});
-    const elapsed = Date.now() - start;
 
-    expect(elapsed).toBeLessThan(3000);
-    // Double quotes craft valid JSONB with extra keys, but no SQL injection occurs;
-    // original counter is untouched
     const verify = await new Parse.Query('SubKeyTest').get(obj.id);
+    // Original counter is untouched
     expect(verify.get('stats').counter).toBe(0);
+    // No injected key exists — the payload is treated as a single literal key name
+    expect(verify.get('stats')['pg_sleep(3)']).toBeUndefined();
   });
 
   it_only_db('postgres')('allows valid Increment on nested object field with normal sub-key', async () => {
diff --git a/src/Adapters/Storage/Postgres/PostgresStorageAdapter.js b/src/Adapters/Storage/Postgres/PostgresStorageAdapter.js
index cd9e51fde3..b65e7d7ed8 100644
--- a/src/Adapters/Storage/Postgres/PostgresStorageAdapter.js
+++ b/src/Adapters/Storage/Postgres/PostgresStorageAdapter.js
@@ -209,6 +209,7 @@ const handleDotFields = object => {
 };
 
 const escapeSqlString = value => value.replace(/'/g, "''");
+const escapeJsonString = value => JSON.stringify(value).slice(1, -1);
 
 const transformDotFieldToComponents = fieldName => {
   return fieldName.split('.').map((cmpt, index) => {
@@ -1766,8 +1767,9 @@ export class PostgresStorageAdapter implements StorageAdapter {
                 }
                 incrementValues.push(amount);
                 const amountIndex = index + incrementValues.length;
-                const safeName = escapeSqlString(c);
-                return `CONCAT('{"${safeName}":', COALESCE($${index}:name->>'${safeName}','0')::int + $${amountIndex}, '}')::jsonb`;
+                const jsonSafeName = escapeSqlString(escapeJsonString(c));
+                const sqlSafeName = escapeSqlString(c);
+                return `CONCAT('{"${jsonSafeName}":', COALESCE($${index}:name->>'${sqlSafeName}','0')::int + $${amountIndex}, '}')::jsonb`;
               })
               .join(' || ');
           // Strip the keys