diff --git a/atst/forms/task_order.py b/atst/forms/task_order.py
index 1c324736..fab3707c 100644
--- a/atst/forms/task_order.py
+++ b/atst/forms/task_order.py
@@ -7,7 +7,7 @@ from wtforms.fields import (
     HiddenField,
 )
 from wtforms.fields.html5 import DateField
-from wtforms.validators import Required, Length, NumberRange, ValidationError
+from wtforms.validators import Required, Length, NumberRange, ValidationError, Regexp
 from flask_wtf import FlaskForm
 from numbers import Number
 
@@ -15,6 +15,7 @@ from .data import JEDI_CLIN_TYPES
 from .fields import SelectField
 from .forms import BaseForm, remove_empty_string
 from atst.utils.localization import translate
+from .validators import REGEX_ALPHA_NUMERIC
 from flask import current_app as app
 
 MAX_CLIN_AMOUNT = 1000000000
@@ -116,7 +117,10 @@ class AttachmentForm(BaseForm):
     filename = HiddenField(
         id="attachment_filename",
         validators=[
-            Length(max=100, message=translate("forms.attachment.filename.length_error"))
+            Length(
+                max=100, message=translate("forms.attachment.filename.length_error")
+            ),
+            Regexp(regex=REGEX_ALPHA_NUMERIC),
         ],
     )
     object_name = HiddenField(
@@ -124,7 +128,8 @@ class AttachmentForm(BaseForm):
         validators=[
             Length(
                 max=40, message=translate("forms.attachment.object_name.length_error")
-            )
+            ),
+            Regexp(regex=REGEX_ALPHA_NUMERIC),
         ],
     )
     accept = ".pdf,application/pdf"
diff --git a/atst/forms/validators.py b/atst/forms/validators.py
index a16bf4f5..ebf29a2a 100644
--- a/atst/forms/validators.py
+++ b/atst/forms/validators.py
@@ -8,6 +8,9 @@ import pendulum
 from atst.utils.localization import translate
 
 
+REGEX_ALPHA_NUMERIC = "^[A-Za-z0-9\-_ \.]*$"
+
+
 def DateRange(lower_bound=None, upper_bound=None, message=None):
     def _date_range(form, field):
         if field.data is None:
diff --git a/js/components/__tests__/upload_input.test.js b/js/components/__tests__/upload_input.test.js
index 43ae48a8..5d613b14 100644
--- a/js/components/__tests__/upload_input.test.js
+++ b/js/components/__tests__/upload_input.test.js
@@ -70,7 +70,7 @@ describe('UploadInput Test', () => {
     })
 
     const component = wrapper.find(uploadinput)
-    const event = { target: { value: '', files: [{ name: '' }] } }
+    const event = { target: { value: '', files: [{ name: 'sample.pdf' }] } }
 
     component.setMethods({
       getUploader: async () => new MockUploader('token', 'objectName'),
diff --git a/js/components/upload_input.js b/js/components/upload_input.js
index cdd9b15e..d7c90bf5 100644
--- a/js/components/upload_input.js
+++ b/js/components/upload_input.js
@@ -1,5 +1,6 @@
 import { buildUploader } from '../lib/upload'
 import { emitFieldChange } from '../lib/emitters'
+import inputValidations from '../lib/input_validations'
 
 export default {
   name: 'uploadinput',
@@ -28,6 +29,7 @@ export default {
       changed: false,
       uploadError: false,
       sizeError: false,
+      filenameError: false,
       downloadLink: '',
     }
   },
@@ -50,6 +52,10 @@ export default {
         this.sizeError = true
         return
       }
+      if (!this.validateFileName(file.name)) {
+        this.filenameError = true
+        return
+      }
 
       const uploader = await this.getUploader()
       const response = await uploader.upload(file)
@@ -71,6 +77,10 @@ export default {
         this.uploadError = true
       }
     },
+    validateFileName: function(name) {
+      const regex = inputValidations.restrictedFileName.match
+      return regex.test(name)
+    },
     removeAttachment: function(e) {
       e.preventDefault()
       this.attachment = null
@@ -118,7 +128,8 @@ export default {
       return (
         (!this.changed && this.initialErrors) ||
         this.uploadError ||
-        this.sizeError
+        this.sizeError ||
+        this.filenameError
       )
     },
     valid: function() {
diff --git a/js/lib/input_validations.js b/js/lib/input_validations.js
index af74f211..80c16a7e 100644
--- a/js/lib/input_validations.js
+++ b/js/lib/input_validations.js
@@ -104,4 +104,11 @@ export default {
     unmask: ['(', ')', '-', ' '],
     validationError: 'Please enter a 10-digit phone number',
   },
+  restrictedFileName: {
+    mask: false,
+    match: /^[A-Za-z0-9\-_ \.]+$/,
+    unmask: [],
+    validationError:
+      'File names can only contain the characters A-Z, 0-9, space, hyphen, underscore, and period.',
+  },
 }
diff --git a/templates/components/upload_input.html b/templates/components/upload_input.html
index e9183f9c..c86b6ab6 100644
--- a/templates/components/upload_input.html
+++ b/templates/components/upload_input.html
@@ -49,6 +49,9 @@
       <template v-if="sizeError">
         <span class="usa-input__message">{{ "forms.task_order.size_error" | translate }}</span>
       </template>
+      <template v-if="filenameError">
+        <span class="usa-input__message">{{ "forms.task_order.filename_error" | translate }}</span>
+      </template>
       {% for error, error_messages in field.errors.items() %}
         <span class="usa-input__message">{{error_messages[0]}}</span>
       {% endfor %}
diff --git a/translations.yaml b/translations.yaml
index 310a88ba..99e2d3b0 100644
--- a/translations.yaml
+++ b/translations.yaml
@@ -292,6 +292,7 @@ forms:
   task_order:
     upload_error: There was an error uploading your file. Please try again. If you encounter repeated problems uploading this file, please contact CCPO.
     size_error: The file you have selected is too large. Please choose a file no larger than 64MB.
+    filename_error: File names can only contain the characters A-Z, 0-9, space, hyphen, underscore, and period.
     defense_component_label: Select DoD component(s) funding your Portfolio
     file_format_not_allowed: Only PDF or PNG files can be uploaded.
     number_description: Task order number (13 digits)