fix: sanitize img tags in markdown via shared SafeImg component (#18112)

web/src/components/highlight-markdown/index.tsx

@@ -32,6 +32,7 @@ import { citationMarkerReg } from '@/utils/citation-utils';
 import { getDirAttribute } from '@/utils/text-direction';
 import { omit } from 'lodash';
 import { useIsDarkTheme } from '../theme-provider';
+import { SafeImg } from '@/components/safe-img';
 import styles from './index.module.less';
 
 const HighLightMarkdown = ({
@@ -60,6 +61,7 @@ const HighLightMarkdown = ({
             p: ({ children, ...props }: any) => (
               <p {...omit(props, 'node')}>{children}</p>
             ),
+            img: SafeImg,
             code(props: any) {
               const { children, className, ...rest } = props;
               const match = /language-(\w+)/.exec(className || '');

web/src/components/markdown-content/index.tsx

@@ -57,6 +57,8 @@ import {
   HoverCardTrigger,
 } from '../ui/hover-card';
 import styles from './index.module.less';
+import { sanitizeHtmlWithImagesAsText } from '@/utils/dom-util';
+import { SafeImg } from '@/components/safe-img';
 
 const getChunkIndex = (match: string) => parseCitationIndex(match);
 
@@ -211,7 +213,7 @@ const MarkdownContent = ({
           <div className={'space-y-2 max-w-[40vw]'}>
             <div
               dangerouslySetInnerHTML={{
-                __html: DOMPurify.sanitize(chunkItem?.content ?? ''),
+                __html: sanitizeHtmlWithImagesAsText(chunkItem?.content ?? ''),
               }}
               className={classNames(styles.chunkContentText)}
               dir="auto"
@@ -303,6 +305,7 @@ const MarkdownContent = ({
             p: ({ children, ...props }: any) => <p {...props}>{children}</p>,
             'custom-typography': ({ children }: { children: string }) =>
               renderReference(children),
+            img: SafeImg,
             code(props: any) {
               const { children, className, ...rest } = props;
               const restProps = omit(rest, 'node');

web/src/components/next-markdown-content/index.tsx

@@ -16,6 +16,7 @@
 
 import Image, { AuthenticatedImg } from '@/components/image';
 import SvgIcon from '@/components/svg-icon';
+import { SafeImg } from '@/components/safe-img';
 import { MarkdownRemarkPlugins } from '@/constants/markdown-remark-plugins';
 import { IReferenceChunk, IReferenceObject } from '@/interfaces/database/chat';
 import { getExtension } from '@/utils/document-util';
@@ -419,7 +420,7 @@ function MarkdownContent({
                 </a>
               );
             },
-            img({ src, alt, ...props }: any) {
+            img({ src, alt, title }: any) {
               if (isArtifactUrl(src)) {
                 return (
                   <ArtifactImage
@@ -429,16 +430,7 @@ function MarkdownContent({
                   />
                 );
               }
-              return (
-                <span className={styles.artifactImageWrapper}>
-                  <img
-                    src={src}
-                    alt={alt || ''}
-                    className={styles.artifactImage}
-                    {...omit(props, 'node')}
-                  />
-                </span>
-              );
+              return <SafeImg src={src} alt={alt} title={title} />;
             },
             code(props: any) {
               const { children, className, ...rest } = props;

web/src/components/safe-img.tsx

@@ -0,0 +1,58 @@
+/*
+ *  Copyright 2026 The InfiniFlow Authors. All Rights Reserved.
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License");
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
+
+import type { ReactNode } from 'react';
+
+interface SafeImgProps {
+  src?: unknown;
+  alt?: string;
+  title?: string;
+}
+
+const SAFE_SRC_REGEXP = /^(https?:|\/|\.\/|\.\.\/|data:image\/)/i;
+
+const buildImgTagString = (src?: unknown, alt?: string, title?: string) => {
+  let tag = '<img';
+  if (src != null) tag += ` src="${src}"`;
+  if (alt != null) tag += ` alt="${alt}"`;
+  if (title != null) tag += ` title="${title}"`;
+  tag += '>';
+  return tag;
+};
+
+/**
+ * Drop all attributes except src/alt/title so event handlers (onerror/onload)
+ * injected via rehypeRaw cannot fire. Used as a react-markdown `img` override.
+ */
+const isSafeImgSrc = (src: unknown): src is string =>
+  typeof src === 'string' && SAFE_SRC_REGEXP.test(src.trim());
+
+/**
+ * Render an <img> safely for react-markdown overrides.
+ *
+ * - Safe src (http(s) / relative / `data:image`): render a real <img>,
+ *   explicitly picking only src/alt/title so event handlers like `onerror` /
+ *   `onload` that rehypeRaw may pass through cannot execute.
+ * - Non-string or unsafe src (`javascript:` / `vbscript:` / unknown
+ *   schemes): render the original `<img>` tag as a literal string. React
+ *   escapes it, so the markup stays visible without executing scripts.
+ */
+export const SafeImg = ({ src, alt, title }: SafeImgProps): ReactNode => {
+  if (!isSafeImgSrc(src)) return <>{buildImgTagString(src, alt, title)}</>;
+  return <img src={src} alt={alt ?? ''} title={title} />;
+};
+
+export default SafeImg;