security: add safeImageUrl, un-break M-5's over-blocking of image-context SVG data URIs

M-5 made safeUrl() block data:image/svg+xml everywhere, including the
image-only sinks (<img src>, CSS url()) that Gallery's default images and
other SVG placeholders rely on. Loaded as an image, an SVG is rasterized
and never executes an inline <script>/onload= -- that only happens when
it's navigated to or loaded as an <iframe> document -- so M-5 over-blocked
the safe contexts and broke every published Gallery (and other components
using an SVG placeholder) using safeUrl's default images in prod.

Adds safeImageUrl(): identical javascript:/vbscript: handling to safeUrl,
but treats data: as an allowlist of image/* subtypes instead of a
blocklist -- allows all data:image/* (including svg+xml, with or without
base64), still blocks data:text/html and any other non-image data: type.

Swapped to safeImageUrl at IMAGE-src / CSS-image url() sinks only:
- Gallery.tsx img src + lightbox data-lb-src
- ImageBlock.tsx img src (toHtml)
- Logo.tsx / Navbar.tsx logo <img> src (their href/link targets keep safeUrl)
- style-helpers.ts sanitizeCssValue's url(...) handling (background-image
  for HeroSimple/BackgroundSection/Section/CallToAction)

Left on safeUrl (href/iframe/form-action/navigation sinks, where
data:image/svg+xml must stay blocked): ButtonLink, Icon link, SocialLinks,
Menu/Navbar link hrefs, PricingTable buttonHref, _cta-helpers,
ContentSlider buttonHref, FeaturesGrid buttonUrl, FormContainer action
(via form-relay-wiring), MapEmbed/VideoBlock iframe src.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

craft/src/components/basic/Logo.tsx

@@ -2,7 +2,7 @@ import React, { CSSProperties } from 'react';
 import { useNode, UserComponent } from '@craftjs/core';
 import { cssPropsToString } from '../../utils/style-helpers';
 import { useSiteDesign } from '../../state/SiteDesignContext';
-import { escapeHtml, escapeAttr, safeUrl } from '../../utils/escape';
+import { escapeHtml, escapeAttr, safeUrl, safeImageUrl } from '../../utils/escape';
 
 /* ---------- Types ---------- */
 
@@ -104,7 +104,7 @@ Logo.craft = {
   let innerHtml: string;
   if (props.type === 'image' && props.imageSrc) {
     const imgStyle = cssPropsToString({ width: props.imageWidth || '120px', height: 'auto', display: 'block' });
-    innerHtml = `<img src="${escapeAttr(safeUrl(props.imageSrc))}" alt="${escapeAttr(props.text || 'Logo')}"${imgStyle ? ` style="${imgStyle}"` : ''} />`;
+    innerHtml = `<img src="${escapeAttr(safeImageUrl(props.imageSrc))}" alt="${escapeAttr(props.text || 'Logo')}"${imgStyle ? ` style="${imgStyle}"` : ''} />`;
   } else {
     const spanStyle = cssPropsToString({
       fontWeight: props.fontWeight || '700',

craft/src/components/basic/Navbar.tsx

@@ -2,7 +2,7 @@ import React, { CSSProperties, useState } from 'react';
 import { useNode, UserComponent } from '@craftjs/core';
 import { cssPropsToString } from '../../utils/style-helpers';
 import { useSiteDesign } from '../../state/SiteDesignContext';
-import { escapeHtml, escapeAttr, safeUrl, cssValue, scopeId } from '../../utils/escape';
+import { escapeHtml, escapeAttr, safeUrl, safeImageUrl, cssValue, scopeId } from '../../utils/escape';
 
 /* ---------- Types ---------- */
 
@@ -252,7 +252,7 @@ Navbar.craft = {
   let logoHtml: string;
   if (props.logoType === 'image' && props.logoImage) {
     const imgStyle = cssPropsToString({ width: props.logoWidth || '120px', height: 'auto', display: 'block' });
-    logoHtml = `<a href="${escapeAttr(safeUrl(logoUrl))}" style="text-decoration:none;display:flex;align-items:center;flex-shrink:0"><img src="${escapeAttr(safeUrl(props.logoImage))}" alt="${escapeAttr(props.logoText || 'Logo')}"${imgStyle ? ` style="${imgStyle}"` : ''} /></a>`;
+    logoHtml = `<a href="${escapeAttr(safeUrl(logoUrl))}" style="text-decoration:none;display:flex;align-items:center;flex-shrink:0"><img src="${escapeAttr(safeImageUrl(props.logoImage))}" alt="${escapeAttr(props.logoText || 'Logo')}"${imgStyle ? ` style="${imgStyle}"` : ''} /></a>`;
   } else {
     const logoStyle = cssPropsToString({
       fontWeight: '700',

craft/src/components/media/ImageBlock.tsx

@@ -1,7 +1,7 @@
 import React, { CSSProperties, useCallback, useRef } from 'react';
 import { useNode, UserComponent } from '@craftjs/core';
 import { cssPropsToString } from '../../utils/style-helpers';
-import { escapeAttr, safeUrl } from '../../utils/escape';
+import { escapeAttr, safeImageUrl } from '../../utils/escape';
 
 export const PLACEHOLDER_SRC = "data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='400' height='300'%3E%3Cdefs%3E%3ClinearGradient id='bg' x1='0' y1='0' x2='0' y2='1'%3E%3Cstop offset='0%25' stop-color='%23f1f5f9'/%3E%3Cstop offset='100%25' stop-color='%23e2e8f0'/%3E%3C/linearGradient%3E%3C/defs%3E%3Crect fill='url(%23bg)' width='400' height='300' rx='12'/%3E%3Crect x='2' y='2' width='396' height='296' rx='10' fill='none' stroke='%23cbd5e1' stroke-width='2' stroke-dasharray='8 4'/%3E%3Cg transform='translate(200,110)'%3E%3Crect x='-28' y='-28' width='56' height='56' rx='12' fill='%23cbd5e1' opacity='0.5'/%3E%3Cpath d='M-12 8 L-4 -2 L2 4 L8 -6 L16 8Z' fill='%2394a3b8'/%3E%3Ccircle cx='-6' cy='-10' r='5' fill='%2394a3b8'/%3E%3C/g%3E%3Ctext x='200' y='160' text-anchor='middle' fill='%2364748b' font-family='Inter,sans-serif' font-size='15' font-weight='500'%3EDrop image here%3C/text%3E%3Ctext x='200' y='182' text-anchor='middle' fill='%2394a3b8' font-family='Inter,sans-serif' font-size='12'%3Eor click to upload%3C/text%3E%3C/svg%3E";
 
@@ -95,5 +95,5 @@ ImageBlock.craft = {
   }
   const s = cssPropsToString({ display: 'block', maxWidth: '100%', ...props.style });
   const alt = props.alt ? ` alt="${escapeAttr(props.alt)}"` : ' alt=""';
-  return { html: `<img src="${escapeAttr(safeUrl(src))}"${alt}${s ? ` style="${s}"` : ''} />` };
+  return { html: `<img src="${escapeAttr(safeImageUrl(src))}"${alt}${s ? ` style="${s}"` : ''} />` };
 };

craft/src/components/sections/Gallery.toHtml.test.ts

@@ -94,6 +94,32 @@ describe('Gallery.toHtml deterministic + unique scope ids (thread node id, no Ma
   });
 });
 
+describe('Gallery.toHtml default SVG placeholder images survive export (Bug 2 regression)', () => {
+  test('a default data:image/svg+xml image emits a non-empty img src, not src=""', () => {
+    const { html } = toHtml({}, ''); // no images prop -> component default SVG placeholders
+    expect(html).not.toContain('src=""');
+    expect(html).toMatch(/src="data:image\/svg\+xml[^"]*"/);
+  });
+
+  test('an explicit data:image/svg+xml gallery image src is preserved (not stripped to empty)', () => {
+    const svg = 'data:image/svg+xml,%3Csvg%2F%3E';
+    const { html } = toHtml({ images: [{ src: svg, alt: 'a' }] }, '');
+    expect(html).toContain(`src="${svg}"`);
+  });
+
+  test('lightbox data-lb-src also preserves data:image/svg+xml (still an image context)', () => {
+    const svg = 'data:image/svg+xml,%3Csvg%2F%3E';
+    const { html } = toHtml({ images: [{ src: svg, alt: 'a' }], lightbox: true }, '');
+    expect(html).toContain(`data-lb-src="${svg}"`);
+  });
+
+  test('a javascript: gallery image src still yields an empty src (safeImageUrl still blocks it)', () => {
+    const { html } = toHtml({ images: [{ src: 'javascript:alert(1)', alt: 'a' }] }, '');
+    expect(html).toContain('src=""');
+    expect(html).not.toContain('javascript:');
+  });
+});
+
 describe('Gallery.toHtml lightbox focus management (M-2)', () => {
   const props = { images: [{ src: '/a.jpg', alt: 'a' }], lightbox: true };
 

craft/src/components/sections/Gallery.tsx

@@ -1,7 +1,7 @@
 import React, { CSSProperties } from 'react';
 import { useNode, UserComponent } from '@craftjs/core';
 import { cssPropsToString } from '../../utils/style-helpers';
-import { escapeHtml, escapeAttr, safeUrl, scopeId, cssValue } from '../../utils/escape';
+import { escapeHtml, escapeAttr, safeImageUrl, scopeId, cssValue } from '../../utils/escape';
 
 interface GalleryImage {
   src: string;
@@ -154,10 +154,10 @@ Gallery.craft = {
     // inline onclick with an interpolated src -- a single delegated click
     // listener below reads it, so a src containing a quote can't break out
     // of a per-item event-handler string.
-    const lbAttr = lightbox ? ` data-lb-src="${escapeAttr(safeUrl(img.src || ''))}" role="button" tabindex="0"` : '';
+    const lbAttr = lightbox ? ` data-lb-src="${escapeAttr(safeImageUrl(img.src || ''))}" role="button" tabindex="0"` : '';
     const itemStyle = lightbox ? 'cursor:pointer;position:relative;overflow:hidden;border-radius:8px' : 'position:relative;overflow:hidden;border-radius:8px';
     return `<div${lbAttr} style="${itemStyle}">
-      <img src="${escapeAttr(safeUrl(img.src || ''))}" alt="${escapeAttr(img.alt)}" style="width:100%;height:200px;object-fit:cover;display:block;border-radius:8px;background-color:#f1f5f9" />
+      <img src="${escapeAttr(safeImageUrl(img.src || ''))}" alt="${escapeAttr(img.alt)}" style="width:100%;height:200px;object-fit:cover;display:block;border-radius:8px;background-color:#f1f5f9" />
       ${caption}
     </div>`;
   }).join('\n    ');

craft/src/utils/escape.test.ts

@@ -1,5 +1,5 @@
 import { describe, test, expect } from 'vitest';
-import { escapeHtml, escapeAttr, safeUrl, stableHash, scopeId, sanitizeFormMethod, sanitizeInputType } from './escape';
+import { escapeHtml, escapeAttr, safeUrl, safeImageUrl, stableHash, scopeId, sanitizeFormMethod, sanitizeInputType } from './escape';
 
 describe('escapeHtml', () => {
   test('escapes &, <, >, "', () => {
@@ -112,6 +112,64 @@ describe('safeUrl', () => {
   });
 });
 
+describe('safeImageUrl (Bug 2: image-context sink -- data:image/svg+xml is safe as an <img>/CSS url() target)', () => {
+  test('allows data:image/svg+xml (a raw, non-base64 SVG data URI, as Gallery/ImageBlock placeholders use)', () => {
+    const s = 'data:image/svg+xml,<svg/>';
+    expect(safeImageUrl(s)).toBe(s);
+  });
+
+  test('allows data:image/svg+xml;base64 variant', () => {
+    const s = 'data:image/svg+xml;base64,PHN2Zy8+';
+    expect(safeImageUrl(s)).toBe(s);
+  });
+
+  test('allows other data:image/* types unchanged', () => {
+    expect(safeImageUrl('data:image/png;base64,x')).toBe('data:image/png;base64,x');
+    expect(safeImageUrl('data:image/jpeg;base64,x')).toBe('data:image/jpeg;base64,x');
+    expect(safeImageUrl('data:image/webp;base64,x')).toBe('data:image/webp;base64,x');
+    expect(safeImageUrl('data:image/gif;base64,x')).toBe('data:image/gif;base64,x');
+  });
+
+  test('still blocks javascript: scheme', () => {
+    expect(safeImageUrl('javascript:alert(1)')).toBe('');
+  });
+
+  test('still blocks vbscript: scheme', () => {
+    expect(safeImageUrl('vbscript:msgbox(1)')).toBe('');
+  });
+
+  test('still blocks data:text/html', () => {
+    expect(safeImageUrl('data:text/html,x')).toBe('');
+  });
+
+  test('still blocks non-image data: types generally (e.g. data:application/...)', () => {
+    expect(safeImageUrl('data:application/javascript,alert(1)')).toBe('');
+  });
+
+  test('blocks obfuscated (whitespace/case) javascript: scheme, same as safeUrl', () => {
+    expect(safeImageUrl('  JavaScript:alert(1)')).toBe('');
+    expect(safeImageUrl('java\tscript:alert(1)')).toBe('');
+    expect(safeImageUrl('&#106;avascript:alert(1)')).toBe('');
+  });
+
+  test('allows ordinary http(s)/relative urls unchanged, same as safeUrl', () => {
+    expect(safeImageUrl('https://example.com/photo.jpg')).toBe('https://example.com/photo.jpg');
+    expect(safeImageUrl('/assets/photo.jpg')).toBe('/assets/photo.jpg');
+    expect(safeImageUrl('')).toBe('');
+  });
+
+  test('coerces non-string to empty string', () => {
+    expect(safeImageUrl(null as any)).toBe('');
+    expect(safeImageUrl(undefined as any)).toBe('');
+  });
+});
+
+describe('safeUrl still blocks data:image/svg+xml (href/iframe/navigation context unchanged by safeImageUrl addition)', () => {
+  test('safeUrl(data:image/svg+xml,...) is still blocked', () => {
+    expect(safeUrl('data:image/svg+xml,<svg onload=alert(1)>')).toBe('');
+  });
+});
+
 describe('stableHash', () => {
   test('same input always produces the same output', () => {
     expect(stableHash('hello')).toBe(stableHash('hello'));

craft/src/utils/escape.ts

@@ -64,20 +64,7 @@ export function safeUrl(s: string): string {
   const trimmed = s.trim();
   if (trimmed === '') return '';
 
-  // Build a normalized copy for scheme detection only: decode numeric HTML
+  const collapsed = normalizeForSchemeCheck(trimmed);
-  // entities (catches e.g. j -> 'j'), strip whitespace/control chars,
-  // and lowercase.
-  const normalized = decodeNumericEntities(trimmed)
-    .replace(/[\x00-\x20]+/g, '')
-    .toLowerCase();
-
-  // Strip any colons before matching the scheme prefix. This defeats
-  // obfuscation that splices extra colons into the scheme name itself
-  // (e.g. decoding : mid-word produces "java:script:alert(1)", which
-  // would otherwise dodge a literal "^javascript:" check) while still
-  // reliably catching the real "javascript:"/"vbscript:"/"data:text/html"
-  // prefixes once their own colon is removed.
-  const collapsed = normalized.replace(/:/g, '');
 
   if (DANGEROUS_SCHEME_PREFIXES.some((prefix) => collapsed.startsWith(prefix))) {
     return '';
@@ -86,6 +73,61 @@ export function safeUrl(s: string): string {
   return trimmed;
 }
 
+/**
+ * Image-context variant of `safeUrl` for IMAGE sinks only (`<img src>`, CSS
+ * `url(...)` backgrounds). `data:image/svg+xml` is safe here -- loaded as an
+ * image, an SVG is rasterized and never executes an inline <script>/onload=
+ * the way it would as a navigation/iframe document -- so, unlike `safeUrl`,
+ * this ALLOWS every `data:image/*` subtype (svg+xml, png, jpeg, gif, webp,
+ * ..., with or without `;base64`).
+ *
+ * Still blocks `javascript:` / `vbscript:` (same obfuscation-resistant
+ * normalization as `safeUrl`), and -- because this is an image sink, not a
+ * general-purpose URL sink -- treats `data:` as an ALLOWLIST rather than a
+ * blocklist: any `data:` URI whose type is NOT `image/*` (`data:text/html`,
+ * `data:application/javascript`, `data:text/javascript`, etc.) is blocked
+ * too, since none of those are legitimate image sources.
+ *
+ * Do NOT use this for href/iframe/form-action/navigation sinks -- keep
+ * those on `safeUrl`, which still blocks `data:image/svg+xml`.
+ */
+export function safeImageUrl(s: unknown): string {
+  if (typeof s !== 'string') return '';
+
+  const trimmed = s.trim();
+  if (trimmed === '') return '';
+
+  const collapsed = normalizeForSchemeCheck(trimmed);
+
+  if (collapsed.startsWith('javascript') || collapsed.startsWith('vbscript')) {
+    return '';
+  }
+  if (collapsed.startsWith('data') && !collapsed.startsWith('dataimage')) {
+    // A data: URI whose MIME type isn't image/* -- e.g. data:text/html,
+    // data:application/javascript, data:text/javascript. No legitimate
+    // image source needs these; block unconditionally.
+    return '';
+  }
+
+  return trimmed;
+}
+
+// Normalizes a trimmed URL string for scheme-prefix matching only: decodes
+// numeric HTML entities (catches e.g. &#106; -> 'j'), strips whitespace /
+// control chars, lowercases, then strips every colon. Stripping colons
+// defeats obfuscation that splices extra colons into the scheme name itself
+// (e.g. decoding &#58; mid-word produces "java:script:alert(1)", which would
+// otherwise dodge a literal "^javascript:" check) while still reliably
+// catching the real "javascript:"/"vbscript:"/"data:..." prefixes once their
+// own colon is removed. Used for prefix `.startsWith()` checks only -- the
+// original (non-collapsed) string is always what gets returned/emitted.
+function normalizeForSchemeCheck(trimmed: string): string {
+  return decodeNumericEntities(trimmed)
+    .replace(/[\x00-\x20]+/g, '')
+    .toLowerCase()
+    .replace(/:/g, '');
+}
+
 /**
  * Neutralizes CSS-context breakout for a single design-token value (color,
  * length, gradient, etc.) so it is safe to interpolate RAW into either CSS

craft/src/utils/style-helpers.ts

@@ -1,5 +1,5 @@
 import { CSSProperties } from 'react';
-import { escapeAttr, safeUrl } from './escape';
+import { escapeAttr, safeImageUrl } from './escape';
 
 const camelToKebab = (str: string): string =>
   str.replace(/[A-Z]/g, (m) => '-' + m.toLowerCase());
@@ -41,8 +41,12 @@ function sanitizeCssValue(raw: string): string {
     // Neutralize the url(...) reference: validate/strip the scheme and
     // re-wrap in single quotes with the contents escaped for attribute
     // safety. This is already fully safe, `;` and all.
+    // Image-context sink (background/mask/border-image url()): use
+    // safeImageUrl, not safeUrl -- a data:image/svg+xml background is safe
+    // (rasterized, never executed as a document) and must survive here, the
+    // same way it must survive on an <img src>.
     const inner = m[2];
-    out += `url('${escapeAttr(safeUrl(inner.trim()))}')`;
+    out += `url('${escapeAttr(safeImageUrl(inner.trim()))}')`;
     lastIndex = URL_RE.lastIndex;
   }
   out += sanitizeBreakoutChars(raw.slice(lastIndex));