From 773787c74c2f57e5779095c9026e1223047198ee Mon Sep 17 00:00:00 2001
From: Timothy Jaeryang Baek <tim@openwebui.com>
Date: Wed, 11 Feb 2026 16:16:41 -0600
Subject: [PATCH] refac

---
 backend/open_webui/models/auths.py   | 10 ++++++-
 backend/open_webui/models/users.py   | 13 +++++++++-
 backend/open_webui/utils/validate.py | 39 ++++++++++++++++++++++++++++
 3 files changed, 60 insertions(+), 2 deletions(-)
 create mode 100644 backend/open_webui/utils/validate.py

diff --git a/backend/open_webui/models/auths.py b/backend/open_webui/models/auths.py
index 2d795cd2b..0b4639fc6 100644
--- a/backend/open_webui/models/auths.py
+++ b/backend/open_webui/models/auths.py
@@ -5,7 +5,8 @@ from typing import Optional
 from sqlalchemy.orm import Session
 from open_webui.internal.db import Base, JSONField, get_db, get_db_context
 from open_webui.models.users import User, UserModel, UserProfileImageResponse, Users
-from pydantic import BaseModel
+from open_webui.utils.validate import validate_profile_image_url
+from pydantic import BaseModel, field_validator
 from sqlalchemy import Boolean, Column, String, Text
 
 log = logging.getLogger(__name__)
@@ -74,6 +75,13 @@ class SignupForm(BaseModel):
     password: str
     profile_image_url: Optional[str] = "/user.png"
 
+    @field_validator("profile_image_url")
+    @classmethod
+    def check_profile_image_url(cls, v: Optional[str]) -> Optional[str]:
+        if v is not None:
+            return validate_profile_image_url(v)
+        return v
+
 
 class AddUserForm(SignupForm):
     role: Optional[str] = "pending"
diff --git a/backend/open_webui/models/users.py b/backend/open_webui/models/users.py
index 4a526d03f..7e398c1e4 100644
--- a/backend/open_webui/models/users.py
+++ b/backend/open_webui/models/users.py
@@ -12,9 +12,10 @@ from open_webui.models.groups import Groups, GroupMember
 from open_webui.models.channels import ChannelMember
 
 from open_webui.utils.misc import throttle
+from open_webui.utils.validate import validate_profile_image_url
 
 
-from pydantic import BaseModel, ConfigDict
+from pydantic import BaseModel, ConfigDict, field_validator
 from sqlalchemy import (
     BigInteger,
     JSON,
@@ -154,6 +155,11 @@ class UpdateProfileForm(BaseModel):
     gender: Optional[str] = None
     date_of_birth: Optional[datetime.date] = None
 
+    @field_validator("profile_image_url")
+    @classmethod
+    def check_profile_image_url(cls, v: str) -> str:
+        return validate_profile_image_url(v)
+
 
 class UserGroupIdsModel(UserModel):
     group_ids: list[str] = []
@@ -237,6 +243,11 @@ class UserUpdateForm(BaseModel):
     profile_image_url: str
     password: Optional[str] = None
 
+    @field_validator("profile_image_url")
+    @classmethod
+    def check_profile_image_url(cls, v: str) -> str:
+        return validate_profile_image_url(v)
+
 
 class UsersTable:
     def insert_new_user(
diff --git a/backend/open_webui/utils/validate.py b/backend/open_webui/utils/validate.py
new file mode 100644
index 000000000..9b50c3b79
--- /dev/null
+++ b/backend/open_webui/utils/validate.py
@@ -0,0 +1,39 @@
+"""Validation utilities for user-supplied input."""
+
+# Known static asset paths used as default profile images
+_ALLOWED_STATIC_PATHS = (
+    "/user.png",
+    "/static/favicon.png",
+)
+
+
+def validate_profile_image_url(url: str) -> str:
+    """
+    Pydantic-compatible validator for profile image URLs.
+
+    Allowed formats:
+    - Empty string (falls back to default avatar)
+    - data:image/* URIs (base64-encoded uploads from the frontend)
+    - Known static asset paths (/user.png, /static/favicon.png)
+
+    Returns the url unchanged if valid, raises ValueError otherwise.
+    """
+    if not url:
+        return url
+
+    _ALLOWED_DATA_PREFIXES = (
+        "data:image/png",
+        "data:image/jpeg",
+        "data:image/gif",
+        "data:image/webp",
+    )
+    if any(url.startswith(prefix) for prefix in _ALLOWED_DATA_PREFIXES):
+        return url
+
+    if url in _ALLOWED_STATIC_PATHS:
+        return url
+
+    raise ValueError(
+        "Invalid profile image URL: only data URIs and default avatars are allowed."
+    )
+