DOMPurify URI-tests srcset as a single string, so an allowed first
candidate waved every later one through - an SVG data: URI could ride
in behind a raster candidate on <img srcset> and <picture><source>.
Check every data: occurrence against the raster allowlist and drop the
whole attribute on one disallowed hit, including the external blocker's
data-blocked-srcset stash, which shares the hook pass with no ordering
guarantee. The token is captured through the metadata-ending comma so
the plain (non-base64) raster form keeps the same verdict as in src.
ALLOWED_URI_REGEXP excludes image/svg+xml on purpose - DOMPurify cannot
inspect the bytes inside a data: URI, so an SVG payload can carry
<script>/<foreignObject> the surrounding sanitizer never sees. That
exclusion never took effect on <img>, <video>, <audio>, <source> and
<track>: DOMPurify's attribute check short-circuits on DATA_URI_TAGS
before ALLOWED_URI_REGEXP is consulted, and that set can only be extended
via ADD_DATA_URI_TAGS, never trimmed. Any data: URI reached those tags,
including image/svg+xml and text/html; <a href> behaved as documented.
Not a live script vector - browsers render SVG-in-<img> in secure static
mode - but the sanitizer promised something it did not enforce, and the
print window renders sanitized bodies without the iframe sandbox and CSP
that otherwise back it up.
restrictDataUriResourcesOnNode re-applies the raster allowlist on those
tags, wired in through the existing afterSanitizeAttributes hooks. The
blocked-external-image placeholder becomes a 1x1 GIF: it is set in the
same hook pass, so an SVG placeholder would depend on hook order.
The three viewer call sites that hand-rolled
DOMPurify.sanitize(html, EMAIL_IFRAME_SANITIZE_CONFIG) now use
sanitizeEmailHtmlForIframe, which is the same thing and picks up the
guard automatically.
Review follow-up to #751.
The offload path could not actually run: onBeforeBlobUpload goes through
HookBus.transform, which capped every handler at the 5s default. A handler
that pushes the file to an external store blows past that, and on timeout
the error is swallowed, the original file id is kept, and the composer
attaches the big file anyway - silently - while three such timeouts in a
minute auto-disable the plugin. Buses can now carry their own per-handler
budget and this one gets 120s. The same ceiling existed inside the sandbox,
where http.post/http.fetch were bounded by the 30s default API timeout;
those two are transfers rather than round-trips and now get 120s as well.
PRIVILEGED_ONLY_METHODS listed 'upfiles.set', which matches no dispatched
method - the dispatcher calls it 'upfiles.save'. So the write was never
tier-gated despite the comment saying it was, and an untrusted plugin with
email:blob-write could replace the bytes of a file the user was about to
send. Fixed the name. Relaxing the read while that stayed open was the
wrong order.
Moving upfiles.get to email:blob-read is kept, but it is a wider grant than
the PR described: onBeforeBlobUpload hands the file id to every registered
handler, so the id is not a secret and any untrusted plugin holding
email:blob-read can read every file the user attaches. The consent copy now
says that; email:blob-write's copy was describing the read and now describes
the replace it actually gates.
Also in the composer offload path:
- sanitize the handler's html before it reaches the document and the sent
message, and insert it through the editor at the caret rather than
concatenating it after the signature and quoted block
- honour an abort that lands while the handler is offloading
- delete the right staged file when the handler re-saved it under a new id
via upfiles.save, which otherwise stranded a copy in IndexedDB forever
External web links (http/https) in rendered email bodies open in a new browser
tab with target="_blank" rel="noopener noreferrer". mailto:, tel:, and in-page
#anchors keep their default behavior instead of spawning a blank tab.
The plaintext render path is already handled on main by #594 (ADD_URI_SAFE_ATTR
in PLAIN_TEXT_RENDERED_CONFIG), so this no longer adds its own hook there — the
plaintext linkifier only ever emits http(s) anchors, so the config's declarative
exemption is sufficient. This change covers the paths #594 did not:
- iframe HTML render: both anchor passes (the DOMPurify hook and the post-render
DOM walk in email-viewer.tsx) set target=_blank on EVERY <a>, including
mailto:/tel:. Now scoped to http(s) via the shared applyNewTabToAnchor()
helper (http/https -> target+rel; mailto/tel/#/other -> strip target/rel).
- sanitizeI18nHtml: the same DOMPurify strip dropped target/rel from translated
links (e.g. the docs link in settings.security.not_available, target="_blank"
in 19/22 locales). Keep the author's target and harden rel="noopener
noreferrer".
Tests: unit coverage for isHttpLinkHref / applyNewTabToAnchor / sanitizeI18nHtml
plus an integration suite over the real plaintext and HTML/iframe render
pipelines. The plaintext-hook-specific cases are dropped as redundant with #594.
Defence-in-depth on top of the strict iframe img-src/media-src/font-src CSP
that already blocks <style>-tag fetches at the network level. The per-node
DOM walk in blockExternalResourcesOnNode only sees element attributes, so a
tracker hidden in a kept <style> block (background url(), @font-face, @import)
never passed through it.
Adds stripExternalStyleSheetCss(), wired into blockExternalResourcesOnNode for
STYLE nodes (so it's gated on shouldBlockExternal and drives the blocked-content
banner like every other vector). Decodes CSS escapes over the whole block first
so the escaped-keyword form \75\72\6C( -> url( is caught - a literal `url(`
match would miss it. Removes remote @import in both url() and bare-string forms.
Signatures render into the main document - the identity form's live preview
and the composer's signature block - rather than the sandboxed iframe used for
message bodies. SIGNATURE_SANITIZE_CONFIG allows no target attribute, so those
anchors were live and target-less: one click navigated the whole app away,
discarding the unsent draft or the unsaved signature with it.
Add sanitizeSignatureHtmlForDisplay, which keeps the storage sanitizer's image
restrictions but forces target="_blank" rel="noopener noreferrer" on every
anchor, and use it at the two render sites. The composer's SignatureBlock
NodeView stamps the target on its rendered DOM instead, because attrs.html is
what serializeEditorContent emits into the sent message - storage and the
recipient's copy stay exactly as the user wrote them.
Plain-text bodies render into the main document rather than the sandboxed
iframe, so an anchor without target="_blank" navigates the whole app away
instead of opening a new tab.
plainTextToSafeHtml emits target and rel correctly, but
sanitizePlainTextRenderedHtml stripped both back off: DOMPurify URI-tests
every attribute value not on its URI-safe list, and "_blank" does not match
PLAIN_TEXT_RENDERED_CONFIG's ALLOWED_URI_REGEXP. EMAIL_SANITIZE_CONFIG avoids
this only because its regex carries a catch-all alternation for non-URI values.
Mark target and rel as URI-safe so they survive the URI test, rather than
loosening href validation.
- Restricts src to https: URLs or base64-embedded raster data: URIs (png/jpeg/gif/webp).
- SVG is excluded for safety reasons.
- Images with a disallowed src are removed entirely so they don't render as broken-image icons.
Inline CID images were replaced with raw JMAP download URLs that require authentication. When the browser loaded these as <img src>, the server responded with WWW-Authenticate: Basic, triggering a native login popup.
- Add fetchBlobAsObjectUrl() to JMAPClient that fetches blobs via authenticated request and returns blob: object URLs
- Update email-viewer and thread-conversation-view to fetch CID images asynchronously with auth, using blob: URLs instead of raw server URLs
- Add ALLOWED_URI_REGEXP to DOMPurify config so blob: URLs are not stripped during sanitization
- Add tests for fetchBlobAsObjectUrl and CID/blob URL sanitization
- Add NavigationRail component (desktop vertical icon sidebar + mobile bottom tab bar)
- Add ConfirmDialog with promise-based useConfirmDialog hook for async confirmation flow
- Add WelcomeBanner onboarding component (one-time display, localStorage persistence)
- Polish login form UX (shake on error, TOTP slide animation, password visibility toggle, session expired banner)
- Add inline form validation with shake animation in email composer and contacts
- Add empty state patterns for contacts (no data vs no search results with contextual actions)
- Improve toast notification system with undo action support and typed durations
- Add WCAG AA prefers-reduced-motion media query, safe area insets, sr-only live regions
- Add template settings tab and keyboard shortcut integration
- Update all 8 locale translations
- Address book with JMAP sync and local fallback (contacts CRUD,
search/filter, composer autocomplete, i18n for 8 languages)
- Fix email layout: remove horizontal scroll, left-side clipping,
and empty spaces from blocked external images in newsletters
- Update all dependencies to latest compatible versions
- Expand i18n from 3 to 8 languages (added ES, IT, DE, NL, PT)
- Upgrade Next.js to 16.1.6 for security patches
This release significantly expands internationalization support and adds comprehensive identity management features.
Internationalization (i18n):
- Add 5 new languages: Spanish, Italian, German, Dutch, Portuguese
- Expand from 3 to 8 total supported languages
- Redesign language switcher for better scalability (dropdown UI)
- Complete translations for all features across all languages
Identity Management:
- Multiple sender identities with per-identity signatures
- Sub-addressing support (user+tag@domain.com)
- Context-aware tag suggestions for sub-addresses
- Identity badges in email viewer and list
- Full CRUD operations for managing identities
Newsletter Management:
- RFC 2369 List-Unsubscribe support (one-click unsubscribe)
- HTTP and mailto unsubscribe methods
- Security validation prevents XSS attacks
- Two-step confirmation with persistent dismissal
Security & Accessibility:
- Dark mode email readability (intelligent color transformation)
- WCAG 2.0 Level AA color contrast compliance
- Comprehensive XSS prevention with validation utilities
- Unit test coverage for security-critical code (57 validation tests)
Testing:
- Add unit tests for validation utilities
- Add unit tests for email sanitization
- Add unit tests for color transformation
- Full test coverage for XSS attack vectors
Linus Rath
dealerweb
Stefan Hildebrandt
honzup
Timo Streule
Linus Rath
Matthieu MALVACHE