CVE‑2026‑1905 — Authenticated (Contributor) Stored XSS in “Sphere Manager” WordPress Plugin: What It Means and What You Should Do

Author: Hong Kong Security Expert  |  Date: 2026-02-13  |  Categories: WordPress Security, Vulnerabilities, Incident Response

摘要： A stored Cross‑Site Scripting (XSS) vulnerability affecting Sphere Manager (versions <= 1.0.2) was assigned CVE‑2026‑1905. It allows an authenticated user with Contributor privileges to craft shortcode attributes (the width attribute) that inject arbitrary HTML/JavaScript. This article provides technical details, detection queries, emergency mitigations (including an MU‑plugin you can drop quickly), and practical advice for responding and hardening your site.

目录

• 发生了什么（简要）
• 10. 技术分析：漏洞是如何工作的
• Why Contributors are riskier than you might think
• Real‑world impact and exploitation scenarios
• How to detect if your site is affected (queries & commands)
• Emergency response plan (step‑by‑step)
• Practical temporary fixes (virtual patching & mu‑plugin)
• Recommended permanent mitigations for developers
• WAF rules and signatures you can apply right away
• Recovery and post‑incident hardening
• Appendix: code snippets, SQL, WP‑CLI, and ModSecurity rule examples

发生了什么（简要）

A stored XSS exists in the Sphere Manager plugin (versions <= 1.0.2). The plugin registers a shortcode that accepts a width attribute. The attribute value is not adequately sanitized or escaped before rendering, which allows an authenticated user with Contributor privileges to include HTML or JavaScript inside the attribute (for example, embedded <script> or event handlers like 5. onload/鼠标悬停). When a page containing this shortcode is rendered, the malicious script executes in the browser of any visitor — including editors and administrators — enabling cookie theft, session hijacking, or other actions in the context of the victim’s site.

CVE reference: CVE‑2026‑1905.

10. 技术分析：漏洞是如何工作的

Shortcodes accept structured attributes and render HTML; when attribute values are taken directly from untrusted users and echoed without proper validation/escaping, XSS is possible.

• Shortcode name: registered by the plugin (e.g. [sphere ...])
• 易受攻击的属性： width
• Vulnerable versions: <= 1.0.2
• 所需权限：贡献者
• 漏洞类别：存储型跨站脚本（XSS）

The plugin prints the width attribute value into HTML/CSS context without adequate sanitization. An attacker can craft values like "><script>...</script> or include event attributes (onerror, 5. onload）或 javascript 的 POST/PUT 有效负载到插件端点： URIs. If the attribute is echoed unescaped, the browser will parse and execute injected markup.

示例（概念）：

[sphere width="100">

Why Contributors are riskier than you might think

Site owners often assume Contributors are harmless because they cannot install plugins or publish. That is an incomplete view:

• Contributors can create content that is previewed by editors or admins; previews can execute scripts in an admin's browser.
• Contributor content may be processed by other plugins, widgets or template parts that call do_shortcode() or otherwise render content in contexts visible to privileged users.
• Shortcodes and user-generated attributes can appear in many places (widgets, profile pages, custom blocks), expanding attack surface.
• An attacker with Contributor access can iterate payloads and attempt social engineering to have an admin open a crafted link or preview.

Real‑world impact and exploitation scenarios

1. Site takeover via administrative session theft

   Malicious scripts can steal cookies or trigger CSRF actions to modify admin accounts or settings.

2. Persistent malware distribution

   Injected payloads can redirect visitors, serve malicious JS, or insert SEO‑damaging content.

3. 网络钓鱼和凭据收集

   Attackers can present fake admin login forms when admins visit infected pages.

4. Content and reputation damage

   Spam, ads, or defacement harms user trust and search rankings.

5. Lateral attacks

   Exfiltrate API tokens or interact with integrated services accessible from the site.

如何检测您的网站是否受到影响

You must scan both content and plugin code. Practical detection steps follow.

1) Search post content for shortcodes with width= and suspicious characters

SQL (phpMyAdmin or WP‑CLI):

SELECT ID, post_title, post_type, post_status
FROM wp_posts
WHERE post_content LIKE '%[sphere%width=%' 
  AND post_status IN ('publish','pending','draft');

To find suspicious payloads (tags or 开* attributes):

SELECT ID, post_title
FROM wp_posts
WHERE post_content REGEXP '\\[sphere[^\\]]*width=.*(\\<|on[a-zA-Z]+=|javascript:)'
  AND post_status IN ('publish','pending','draft');

WP‑CLI approach (shell):

# Find posts with 'width=' inside sphere shortcodes
wp post list --post_type=post,page --field=ID | xargs -I % wp post get % --field=post_content | grep -n '\[sphere' -B2 -A2 | grep 'width='

Or a filesystem grep if you have backups or exports:

grep -R --line-number '\[sphere[^]]*width=' wp-content/

2) Search database for <script or event handlers

SELECT ID, post_title FROM wp_posts WHERE post_content LIKE '%<script%' OR post_content LIKE '%onerror=%';

3) Check user activity: find Contributor accounts with recent edits

SELECT ID, user_login, user_email 
FROM wp_users u
JOIN wp_usermeta m ON u.ID = m.user_id AND m.meta_key = 'wp_capabilities'
WHERE m.meta_value LIKE '%contributor%';

Cross‑map 发帖作者 在 wp_posts to these users.

4) Scan for malicious files and injected code

Run a malware scanner or code integrity checker. Inspect wp-content/uploads for unexpected PHP files or unknown files that could be backdoors.

5) Server logs

Inspect access logs for suspicious admin preview requests, POSTs to /wp-admin/post.php containing payloads, or unusual IPs tied to Contributor accounts.

Emergency response plan (step‑by‑step)

1. 将网站置于维护模式 — reduce exposure while you triage.
2. 创建完整备份 (files + DB) before any cleanup for forensic purposes.
3. 更换凭据 — force password resets for all admin users; consider resetting contributor passwords and invalidate active sessions.
4. 删除或停用易受攻击的插件 — deactivate Sphere Manager until a secure update is available. If deactivation risks breaking the site, at minimum prevent shortcode processing (see temporary fixes).
5. Clean malicious content — use the SQL and WP‑CLI queries above to identify and remove malicious shortcodes or sanitize attributes.
6. Scan and remove backdoors — check for injected PHP files, unknown admin users, or rogue scheduled events.
7. 监控日志和流量 — watch for suspicious POSTs, spikes, or new registrations.
8. Apply temporary server/WAF rules — block POSTs to admin endpoints that contain suspicious patterns (examples below).
9. 记录并沟通 — record actions taken and inform stakeholders as needed.

Practical temporary fixes (virtual patching & mu‑plugin)

If an official patch is not yet available, use one or more of these mitigations.

A) Disable or sanitize the shortcode via an MU‑plugin (fast, low risk)

Drop the following as an MU‑plugin file in wp-content/mu-plugins/shortcode-mitigate.php. This wrapper enforces a strict width policy and attempts to preserve original behavior if possible.

<?php
/*
Plugin Name: Shortcode Short-circuit Mitigation
Description: Temporary override to sanitize 'width' attribute for the 'sphere' shortcode.
Version: 1.0
Author: Site Security Team
*/

add_action( 'init', function() {
    if ( shortcode_exists( 'sphere' ) ) {
        global $shortcode_tags;
        if ( isset( $shortcode_tags['sphere'] ) ) {
            $GLOBALS['original_sphere_handler'] = $shortcode_tags['sphere'];
            remove_shortcode( 'sphere' );
        }
    }
    add_shortcode( 'sphere', 'safe_sphere_shortcode' );
} );

function safe_sphere_shortcode( $atts, $content = null ) {
    $atts = shortcode_atts( array(
        'width' => '',
    ), $atts, 'sphere' );

    $width = $atts['width'];

    // Allow only digits and optional '%' sign, and limit length
    $width = preg_replace( '/[^0-9%]/', '', $width );
    if ( strlen( $width ) > 6 ) {
        $width = substr( $width, 0, 6 );
    }

    $safe_width = esc_attr( $width );
    $safe_content = wp_kses_post( $content );

    if ( isset( $GLOBALS['original_sphere_handler'] ) && is_callable( $GLOBALS['original_sphere_handler'] ) ) {
        $sanitized_atts = array( 'width' => $safe_width );
        return call_user_func( $GLOBALS['original_sphere_handler'], $sanitized_atts, $safe_content );
    }

    return '<div class="sphere" style="width:' . $safe_width . ';">' . $safe_content . '</div>';
}
?>

注意：

• This runs as an MU‑plugin (loaded before regular plugins) and is difficult for non‑admins to remove.
• The wrapper sanitizes width to digits and the percent sign only, and sanitizes content with wp_kses_post().

B) Strip width attributes at render time

If you prefer to remove the problematic attribute entirely, add a content filter that strips width inside [sphere] shortcodes:

add_filter( 'the_content', function( $content ) {
    $content = preg_replace_callback( '/\[sphere([^\]]*)\]/i', function( $m ) {
        $attrs = $m[1];
        $attrs = preg_replace( '/\swidth\s*=\s*("|\')[^"\']*\1/i', '', $attrs );
        return '[sphere' . $attrs . ']';
    }, $content );
    return $content;
}, 20 );

C) Server/WAF rule (block suspicious post updates)

If you manage the server or have a WAF, add a temporary rule to block POST submissions containing dangerous width patterns. Example ModSecurity-style conceptual rule:

SecRule REQUEST_URI "@beginsWith /wp-admin/post.php" \
  "phase:2,chain,deny,status:403,msg:'Block suspicious sphere width payloads',log"
  SecRule ARGS_POST "@rx width\s*=\s*\"[^\"]*(

SecRule REQUEST_METHOD "POST" \
  "phase:2,chain,deny,status:403,msg:'Blocked suspicious shortcode width attribute'"
SecRule ARGS_POST "(?i)width\s*=\s*\"[^\"]*(<script|on[a-z]+=|javascript:)[^\"]*\"" "t:none"

# List post IDs that likely contain sphere shortcodes with width attributes
wp post list --post_type='post,page' --format=csv --fields=ID,post_title | while IFS=, read ID TITLE; do
  content=$(wp post get $ID --field=post_content)
  if echo "$content" | grep -qE '\[sphere[^]]*width='; then
    echo "Possible match: $ID - $TITLE"
  fi
done

UPDATE wp_posts
SET post_content = REGEXP_REPLACE(post_content, '\\[sphere([^\\]]*)\\swidth\\s*=\\s*("|\') [^"\\']* \\1([^\\]]*)\\]', '[sphere\\1\\3]')
WHERE post_content REGEXP '\\[sphere[^\\]]*\\swidth\\s*=\\s*("|\')';

// Use strict validation - allow only integer or percentage
function sphere_sanitize_width( $value ) {
    $value = trim( $value );
    if ( preg_match( '/^\d+%?$/', $value ) ) {
        return $value;
    }
    return '100%';
}

// Usage in shortcode handler:
$width = isset( $atts['width'] ) ? sphere_sanitize_width( $atts['width'] ) : '100%';
echo '<div style="width: ' . esc_attr( $width ) . ';">' . wp_kses_post( $content ) . '</div>';

# Block POSTs that contain script tags or event handlers inside width attribute
SecRule REQUEST_METHOD "POST" "phase:2,deny,log,status:403,msg:'Blocked suspicious width attribute payload'"
SecRule ARGS_POST "(?i)width\s*=\s*\"[^\"]*(<script|on[a-z]+=|javascript:)[^\"]*\"" "t:none"