Safe SVG: SVG upload and security sanitization

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Vulnerabilities

6 Total

6 Patched

0 Active

100% Resolved rate

Safe SVG <= 2.2.5 - Authenticated (Author+) Stored Cross-Site Scripting via SVG

CWE-79 · Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

The Safe SVG plugin for WordPress is vulnerable to Stored Cross-Site Scripting via SVG File uploads in all versions up to, and including, 2.2.5 due to insufficient input sanitization and output escaping. This makes it possible for authenticated attackers, with Author-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses the SVG file.

5.4 Medium Affected All - 2.2.5 Patched in ✓ 2.2.6 Published 17 Oct 2024 CVE CVE-2024-8378

SVG Sanitizer library <= 0.15.4 - Cross-Site Scripting Bypass

CWE-79 · Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

The SVG Sanitizer library is vulnerable to XSS Bypass in versions up to, and including, 0.15.4. This may allow an attacker to successfully upload an SVG with persistent Cross-Site Scripting payloads in cases where a plugin is using this library to safely process SVG files.

7.2 High Affected All - 2.0.3 Patched in ✓ 2.1.0 Published 23 Mar 2023 CVE CVE-2023-28426

Safe SVG <= 1.9.9 - Content-Type Bypass

CWE-79 · Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

The sanitisation step of the Safe SVG WordPress plugin before 1.9.10 can be bypassed by spoofing the content-type in the POST request to upload a file. Exploiting this vulnerability, an attacker will be able to perform the kinds of attacks that this plugin should prevent (mainly XSS, but depending on further use of uploaded SVG files potentially other XML attacks).

7.7 High Affected All - 1.9.10 Patched in ✓ 1.9.10 Published 25 Mar 2022 CVE CVE-2022-1091

Safe SVG <= 1.9.5 - Cross-Site Scripting

CWE-79 · Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

The Safe SVG plugin for WordPress is vulnerable to Cross-Site Scripting in versions up to, and including, 1.9.5 due to insufficient input sanitization and output escaping. This makes it possible for attackers to inject arbitrary web scripts that execute in a victim's browser.

5.4 Medium Affected All - 1.9.5 Patched in ✓ 1.9.6 Published 8 Nov 2019

Safe SVG <= 1.9.4 - Denial of Service

CWE-400 · Uncontrolled Resource Consumption

A Denial Of Service vulnerability exists in the safe-svg (aka Safe SVG) plugin through 1.9.4 for WordPress, related to unlimited recursion for a '' substring.

6.5 Medium Affected All - 1.9.4 Patched in ✓ 1.9.5 Published 5 Nov 2019 CVE CVE-2019-18854

Safe SVG <= 1.9.4 - Denial of Service

CWE-400 · Uncontrolled Resource Consumption

A Denial Of Service vulnerability exists in the safe-svg (aka Safe SVG) plugin through 1.9.4 for WordPress, related to potentially unwanted elements or attributes.

6.5 Medium Affected All - 1.9.4 Patched in ✓ 1.9.5 Published 5 Nov 2019 CVE CVE-2019-18855

About Safe SVG

Enable SVG uploads and sanitize them to stop XML/SVG vulnerabilities in your WordPress website.

Safe SVG is the best way to Allow SVG Uploads in WordPress!

It gives you the ability to allow SVG uploads whilst making sure that they’re sanitized to stop SVG/XML vulnerabilities affecting your site. It also gives you the ability to preview your uploaded SVGs in the media library in all views.

Current Features

Sanitised SVGs – Don’t open up security holes in your WordPress site by allowing uploads of unsanitised files.
SVGO Optimisation – Runs your SVGs through the SVGO tool on upload to save you space. This feature is disabled by default but can be enabled by adding the following code: add_filter( 'safe_svg_optimizer_enabled', '__return_true' );
View SVGs in the Media Library – Gone are the days of guessing which SVG is the correct one, we’ll enable SVG previews in the WordPress media library.
Choose Who Can Upload – Restrict SVG uploads to certain users on your WordPress site or allow anyone to upload.

Initially a proof of concept for #24251.

SVG Sanitization is done through the following library: https://github.com/darylldoyle/svg-sanitizer.

SVG Optimization is done through the following library: https://github.com/svg/svgo.

Technical: Upload Path Security

WordPress’s _wp_handle_upload( $file, $action ) function allows any $action value, which determines the filter hook name: {$action}_prefilter. Safe SVG hooks common actions like wp_handle_upload and wp_handle_sideload, but cannot hook arbitrary custom actions defined by third-party code. Since upload actions are unbounded and MIME allowances are global, we cannot guarantee sanitization coverage across all possible upload paths.

Frequently Asked Questions

Can we change the allowed attributes and tags?

Yes, this can be done using the svg_allowed_attributes and svg_allowed_tags filters.
They take one argument that must be returned. See below for examples:

add_filter( 'svg_allowed_attributes', function ( $attributes ) {

    // Do what you want here...

    // This should return an array so add your attributes to
    // to the $attributes array before returning it. E.G.

    $attributes[] = 'target'; // This would allow the target="" attribute.

    return $attributes;
} );


add_filter( 'svg_allowed_tags', function ( $tags ) {

    // Do what you want here...

    // This should return an array so add your tags to
    // to the $tags array before returning it. E.G.

    $tags[] = 'use'; // This would allow the <use> element.

    return $tags;
} );

Can my theme style an inline SVG?

Mostly, yes. The Inline SVG block renders an SVG that carries its own <style> element inside a shadow root, because CSS inside an inline SVG is otherwise applied to the whole page rather than just the SVG. Stylesheets cannot reach into a shadow root, so theme CSS such as .entry-content svg { fill: red; } will not apply to those SVGs.

Inherited properties still cross the boundary, so setting color on an ancestor and using currentColor inside the SVG works, as do CSS custom properties. SVGs that do not contain a <style> element are rendered without the shadow root and can be styled by theme stylesheets.

To turn isolation off, at the cost of allowing an SVG’s CSS to affect the rest of the page:

add_filter( 'safe_svg_inline_use_shadow_dom', '__return_false' );

Why doesn’t Safe SVG globally enable SVG uploads?

Safe SVG only allows SVGs through upload paths it can actively sanitize. While most WordPress uploads use standard functions like wp_handle_upload() (which Safe SVG hooks), plugins and themes can create custom upload paths by calling WordPress’s underlying _wp_handle_upload() function with arbitrary action parameters.

Globally enabling the image/svg+xml MIME type would allow SVGs through all upload paths—including custom ones Safe SVG cannot intercept and sanitize. This would create security vulnerabilities where unsanitized SVGs containing malicious scripts could be uploaded.

This is a deliberate design decision: Safe SVG prioritizes guaranteed sanitization over broad compatibility. SVGs are only allowed when we can ensure they’re safe.

Where do I report security bugs found in this plugin?

Please report security bugs found in the source code of the Safe SVG plugin through the Patchstack Vulnerability Disclosure Program. The Patchstack team will assist you with verification, CVE assignment, and notify the developers of this plugin.

Ratings & Reviews

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Changelog

2.5.0 – 2026-09-07

Security: Prevented direct access of PHP files (props @mehrazmorshed, @dkotter via #300).
Security: The Inline SVG block now renders SVGs that carry their own <style> element inside a shadow root, so their CSS is scoped to the block instead of applying to the whole page (props @darylldoyle, @dkotter, @jeffpaul, @peterwilsoncc via #328).
Security: Bump enshrined/svg-sanitize from ^0.22.0 to ^1.0.0 to pull in security fixes (props @dkotter, @jeffpaul, @peterwilsoncc via #327).
Added: Link support for the SVG Inline block, including URL input, new tab toggle, and nofollow/sponsored rel options (props @vegetable-bits, @mgiannopoulos24, @jeffpaul, @thrijith, @peterwilsoncc, @dkotter, @pbiron via #315).
Added: New safe_svg_inline_use_shadow_dom filter to control which inline SVGs are isolated in a shadow root, and new safe_svg_inline_shadow_styles filter to adjust the CSS injected alongside them (props @darylldoyle, @dkotter, @jeffpaul, @peterwilsoncc via #328).
Added: New safe_svg_remove_remote_references filter to strip remote url(), @import and image-set() references, along with remote href targets, from uploaded SVGs. Off by default, because legitimate SVGs reference remote fonts and images but use this filter to turn it on (props @darylldoyle, @dkotter, @jeffpaul, @peterwilsoncc via #328).
Added: Added support for Enable Media Replace plugin (props @gthayer, @jeffpaul, @peterwilsoncc via #285).
Changed: Bump WordPress minimum supported version to 6.9 (props @zamanq, @peterwilsoncc via #320).
Changed: Bump “tested up to header” to indicate WordPress 7.1 support (props @navi151, @peterwilsoncc, @dkotter, @jeffpaul, @zamanq via #290, #311, #320).
Changed: Theme CSS can no longer target an inline SVG that carries its own <style> element, because stylesheets cannot reach into a shadow root. Style those SVGs from within the SVG itself, or opt out with the safe_svg_inline_use_shadow_dom filter. Inherited properties, including color/currentColor and custom properties, still apply as before, and SVGs without a <style> element are unaffected (props @darylldoyle, @dkotter, @jeffpaul, @peterwilsoncc via #328).
Changed: Updated blueprint file for WordPress.org live previews (props @fellyph, @jeffpaul, @peterwilsoncc via #287).
Changed: Bump svgo from 3.2.0 to 3.3.5 (props @dependabot[bot], @jeffpaul, @peterwilsoncc, @dependabot via #309).

2.4.0 – 2025-09-22

Added: Ability to upload SVGs from more admin locations (props @stormrockwell, @darylldoyle, @wpexplorer, @smerriman, @jeffpaul, @dkotter via #279).
Changed: Added $attachment_id argument to filters safe_svg_use_width_height_attributes and safe_svg_dimensions (props @roborourke, @dkotter via #278).
Fixed: Inconsistent or incorrect data type for $svg argument in the filters safe_svg_use_width_height_attributes and safe_svg_dimensions (props @roborourke, @dkotter via #278).

2.3.3 – 2025-08-13

Security: Update the enshrined/svg-sanitize package from 0.19.0 to 0.22.0 to fix an issue with case-insensitive attributes slipping through the sanitiser and address PHP 8.4 deprecation warnings (props @darylldoyle, @sudar, @georgestephanis, @dkotter, @realazizk via #268, #272).
Security: Bump form-data from 4.0.0 to 4.0.4 (props @dependabot, @faisal-alvi via #270).
Security: Bump tmp from 0.2.3 to 0.2.5 and @inquirer/editor from 4.2.9 to 4.2.16 (props @dependabot, @dkotter via #271).

2.3.2 – 2025-07-21

Fixed: Visual parity between the front end and the block editor (props @s3rgiosan, @dkotter via #261, #266).
Changed: Bump WordPress “tested up to” version 6.8 (props @godleman, @jeffpaul, @dkotter via #251, #254).
Changed: Bump WordPress minimum supported version to 6.6 (props @godleman, @jeffpaul, @dkotter via #254).
Security: Bump ws from 7.5.10 to 8.18.0, @wordpress/scripts from 27.9.0 to 30.6.0, nanoid from 3.3.7 to 3.3.8 and mocha from 10.2.0 to 11.0.1 (props @dependabot, @peterwilsoncc via #245).
Security: Bump @babel/runtime from 7.23.9 to 7.27.0, axios from 1.7.4 to 1.8.4, cookie from 0.4.2 to 0.7.1, express from 4.21.0 to 4.21.2 and @wordpress/e2e-test-utils-playwright from 0.26.0 to 1.20.0 (props @dependabot, @dkotter via #250).
Security: Bump http-proxy-middleware from 2.0.6 to 2.0.9 (props @dependabot, @iamdharmesh via #253).
Security: Bump tar-fs from 3.0.8 to 3.0.9 (props @dependabot, @dkotter via #258).
Security: Bump bytes from 3.0.0 to 3.1.2 and compression from 1.7.4 to 1.8.1 (props @dependabot, @dkotter via #265).

2.3.1 – 2024-12-05

Fixed: Revert changes made to how we determine custom dimensions for SVGs (props @dkotter, @martinpl, @subfighter3, @smerriman, @gigatyrant, @jeffpaul, @iamdharmesh via #238).

2.3.0 – 2024-11-25

Added: New setting that allows large SVG files (roughly 10MB or greater) to be uploaded and sanitized properly (props @kirtangajjar, @faisal-alvi, @darylldoyle, @manojsiddoji, @dkotter via #201).
Added: New get_svg_dimensions function in order to reduce code duplication (props @gabriel-glo, @jeremymoore, @darylldoyle, @iamdharmesh, @dkotter via #216).
Changed: Updated the enshrined/svg-sanitize package from 0.16.0 to 0.19.0 to fix a PHP 8.3 compatibility issue (props @sksaju, @TylerB24890, @darylldoyle, @rolf-yoast, @faisal-alvi via #214).
Changed: Update how image dimensions are passed in get_image_tag_override and one_pixel_fix methods (props @gabriel-glo, @jeremymoore, @darylldoyle, @iamdharmesh, @dkotter via #216).
Changed: Bump WordPress “tested up to” version to 6.7 (props @colinswinney, @jeffpaul via #232, #233).
Changed: Bump WordPress minimum from 6.4 to 6.5 (props @colinswinney, @jeffpaul via #232, #233).
Changed: Remove composer dev dependencies from archived project (props @TylerB24890, @szepeviktor, @peterwilsoncc via #220).
Fixed: Use proper block category for the Safe SVG Icon block (props @kirtangajjar, @fabiankaegy via #226).
Security: Only allow SVG file types to be uploaded if our sanitizer is able to run on those files (props @darylldoyle, @xknown, @dkotter via #228).
Security: Bump webpack from 5.90.1 to 5.94.0 (props @dependabot, @peterwilsoncc via #222).
Security: Bump ws from 7.5.10 to 8.18.0, serve-static from 1.15.0 to 1.16.2 and express from 4.19.2 to 4.21.0 (props @dependabot, @Sidsector9, @faisal-alvi via #227, #230, #234).

2.2.6 – 2024-08-28

Changed: Bump WordPress “tested up to” version to 6.6 (props @sudip-md, @ankitguptaindia, @jeffpaul via #212, #213).
Changed: Bump WordPress minimum from 5.7 to 6.4 (props @sudip-md, @ankitguptaindia, @jeffpaul via #212, #213).
Security: Add svg sanitization on the wp_handle_sideload_prefilter filter (props @dkotter, @xknown, @iamdharmesh via GHSA-3vr7-86pg-hf4g).
Security: Bump braces from 3.0.2 to 3.0.3, pac-resolver from 7.0.0 to 7.0.1, socks from 2.7.1 to 2.8.3, ws from 7.5.9 to 7.5.10 and remove ip (props @dependabot, @Sidsector9 via #206).
Security: Bump axios from 1.6.7 to 1.7.4 (props @dependabot, @faisal-alvi via #218).