diff --git a/files/helpers/sanitize.py b/files/helpers/sanitize.py
index fc1ffcc52..1c6722e58 100644
--- a/files/helpers/sanitize.py
+++ b/files/helpers/sanitize.py
@@ -11,6 +11,8 @@ from random import random, choice
 import signal
 import time
 import requests
+import cssutils
+import tldextract
 
 TLDS = ('ac','ad','ae','aero','af','ag','ai','al','am','an','ao','aq','ar','arpa','as','asia','at','au','aw','ax','az','ba','bb','bd','be','bf','bg','bh','bi','biz','bj','bm','bn','bo','br','bs','bt','bv','bw','by','bz','ca','cafe','cat','cc','cd','cf','cg','ch','ci','ck','cl','club','cm','cn','co','com','coop','cr','cu','cv','cx','cy','cz','de','dj','dk','dm','do','dz','ec','edu','ee','eg','er','es','et','eu','fi','fj','fk','fm','fo','fr','ga','gb','gd','ge','gf','gg','gh','gi','gl','gm','gn','gov','gp','gq','gr','gs','gt','gu','gw','gy','hk','hm','hn','hr','ht','hu','id','ie','il','im','in','info','int','io','iq','ir','is','it','je','jm','jo','jobs','jp','ke','kg','kh','ki','km','kn','kp','kr','kw','ky','kz','la','lb','lc','li','lk','lr','ls','lt','lu','lv','ly','ma','mc','md','me','mg','mh','mil','mk','ml','mm','mn','mo','mobi','mp','mq','mr','ms','mt','mu','museum','mv','mw','mx','my','mz','na','name','nc','ne','net','nf','ng','ni','nl','no','np','nr','nu','nz','om','org','pa','pe','pf','pg','ph','pk','pl','pm','pn','post','pr','pro','ps','pt','pw','py','qa','re','ro','rs','ru','rw','sa','sb','sc','sd','se','sg','sh','si','sj','sk','sl','sm','sn','so','social','sr','ss','st','su','sv','sx','sy','sz','tc','td','tel','tf','tg','th','tj','tk','tl','tm','tn','to','tp','tr','travel','tt','tv','tw','tz','ua','ug','uk','us','uy','uz','va','vc','ve','vg','vi','vn','vu','wf','win','ws','xn','xxx','xyz','ye','yt','yu','za','zm','zw')
 
@@ -326,3 +328,20 @@ def filter_emojis_only(title, edit=False, graceful=False):
 
 	if len(title) > 1500 and not graceful: abort(400)
 	else: return title
+
+
+def sanitize_css(rule):		
+	if isinstance(rule, cssutils.css.CSSStyleRule):
+		
+		for property in rule.style.children():
+			for pv in property.propertyValue:
+				if isinstance(pv, cssutils.css.URIValue):
+					domain = tldextract.extract(pv.uri).registered_domain
+					if domain not in approved_embed_hosts:
+						return f"The domain '{domain}' is not allowed, please use one of these domains\n\n{approved_embed_hosts}."
+
+	if getattr(rule, "children", None):
+		for child in rule.children():
+			clean_block(child)
+		
+	return False
\ No newline at end of file
diff --git a/files/routes/settings.py b/files/routes/settings.py
index ecc7d76da..d2ceddbb3 100644
--- a/files/routes/settings.py
+++ b/files/routes/settings.py
@@ -12,6 +12,7 @@ from files.helpers.sanitize import filter_emojis_only
 from files.helpers.discord import add_role
 from shutil import copyfile
 import requests
+import cssutils
 
 GUMROAD_TOKEN = environ.get("GUMROAD_TOKEN", "").strip()
 GUMROAD_ID = environ.get("GUMROAD_ID", "tfcvri").strip()
@@ -641,6 +642,19 @@ def settings_profilecss_get(v):
 @auth_required
 def settings_profilecss(v):
 	profilecss = request.values.get("profilecss").strip().replace('\\', '').strip()[:4000]
+
+	parser = cssutils.CSSParser(raiseExceptions=True,fetcher=lambda url: None)
+
+	try: css = parser.parseString(profilecss)
+	except Exception as e: return {"error": str(e)}, 400
+
+	for rule in css:
+		error = sanitize_css(rule)
+		if error: return render_template("settings_profilecss.html", error=error, v=v)
+
+	profilecss = css.cssText.decode('utf-8')
+
+
 	v.profilecss = profilecss
 	g.db.add(v)
 	g.db.commit()
diff --git a/files/routes/subs.py b/files/routes/subs.py
index c657aa17b..81c0daa9f 100644
--- a/files/routes/subs.py
+++ b/files/routes/subs.py
@@ -1,10 +1,10 @@
 from files.__main__ import app, limiter, mail
 from files.helpers.alerts import *
 from files.helpers.wrappers import *
+from files.helpers.sanitize import sanitize_css
 from files.classes import *
 from .front import frontlist
-
-
+import cssutils
 
 @app.post("/exile/post/<pid>")
 @is_not_permabanned
@@ -336,7 +336,23 @@ def post_sub_css(v, sub):
 	
 	if not v.mods(sub.name): abort(403)
 
-	sub.css = request.values.get('css', '').strip()
+	css = request.values.get('css', '').strip()
+
+
+	parser = cssutils.CSSParser(raiseExceptions=True,fetcher=lambda url: None)
+
+	try: css = parser.parseString(css)
+	except Exception as e: return {"error": str(e)}, 400
+
+	for rule in css:
+		error = sanitize_css(rule)
+		if error: return render_template('sub/settings.html', v=v, sidebar=sub.sidebar, sub=sub, error=error)
+
+	css = css.cssText.decode('utf-8')
+
+	sub.css = css
+
+
 	g.db.add(sub)
 
 	g.db.commit()
diff --git a/files/templates/sub/settings.html b/files/templates/sub/settings.html
index ee12498a9..6bed2ad37 100644
--- a/files/templates/sub/settings.html
+++ b/files/templates/sub/settings.html
@@ -4,6 +4,18 @@
 
 {% block content %}
 
+{% if error %}
+<div class="alert alert-danger alert-dismissible fade show mb-3 mt-4" role="alert">
+	<i class="fas fa-exclamation-circle my-auto"></i>
+	<span>
+		{{error}}
+	</span>
+	<button class="close" data-bs-dismiss="alert" aria-label="Close">
+		<span aria-hidden="true"><i class="far fa-times"></i></span>
+	</button>
+</div>
+{% endif %}
+
 {% if msg %}
 	<div class="alert alert-success alert-dismissible fade show my-3" role="alert">
 		<i class="fas fa-check-circle my-auto" aria-hidden="true"></i>
@@ -111,8 +123,6 @@
 	</div>
 </div>
 
-
-
 <div class="row">
 	<div class="col col-md-8">
 		<div class="settings">
diff --git a/requirements.txt b/requirements.txt
index bf19a09f5..c64a22ef3 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,5 +1,6 @@
 beautifulsoup4
 bleach==4.1.0
+cssutils
 Flask
 Flask-Caching
 Flask-Compress
@@ -20,9 +21,10 @@ qrcode
 redis
 requests
 SQLAlchemy
+tldextract
 psycopg2-binary
 pusher_push_notifications
 pyenchant
 youtube-dl
 yattag
-webptools
+webptools
\ No newline at end of file