dbcve.org
Cross-site Scripting (XSS)Weakness · CWE-79

CVE-2026-8877

MEDIUM · 6.4 CVSS v3.1 Published 2026-05-27
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
70/100
Remediation priority · Elevated
Remotely reachable Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
The Responsive Video Embedder plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'rem_video' shortcode in versions up to, and including, 0.1. This is due to insufficient input sanitization and output escaping on user supplied attributes (notably 'id' and 'list') in the video_shortcode() function, which are concatenated directly into an HTML iframe's src attribute without escaping. This makes it possible for authenticated attackers, with contributor-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

The Responsive Video Embedder WordPress plugin (versions up to 0.1) contains a stored XSS vulnerability in the video_shortcode() function. The 'id' and 'list' attributes of the rem_video shortcode are not sanitized before being concatenated directly into an iframe's src attribute, allowing authenticated contributors+ to inject arbitrary JavaScript.

MitigationUpgrade to a patched version of the plugin that implements proper input sanitization using WordPress escaping functions like esc_attr() and esc_url() on the id and list parameters before inserting them into HTML attributes.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
None
Scope
Changed
Confidentiality
Low
Integrity
Low
Availability
None

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Confirm the plugin is installed
    Navigate to WordPress admin dashboard, go to Plugins > Installed Plugins, and look for 'Responsive Video Embedder' in the list. Note the version number displayed.
    Affected if The plugin is present and its version is listed as 0.1 or lower
  2. Locate the vulnerable shortcode function
    Access the plugin files via FTP or file manager. Look in the plugin directory (typically wp-content/plugins/responsive-video-embedder/) for the main plugin file containing the video_shortcode() function.
    Affected if The video_shortcode() function exists in the plugin files
  3. Inspect the id attribute handling
    Open the file containing video_shortcode() and locate where the 'id' attribute from the rem_video shortcode is used in an iframe src attribute. Look for direct concatenation without sanitization functions like esc_attr() or esc_url().
    Affected if The 'id' attribute is concatenated directly into the iframe src without proper escaping (e.g., no esc_url() or esc_attr() call)
  4. Inspect the list attribute handling
    In the same function, locate where the 'list' attribute is handled. Check if it is also concatenated directly into the iframe src without sanitization.
    Affected if The 'list' attribute is concatenated directly into the iframe src without proper escaping
  5. Check for active use of the vulnerable shortcode
    Search your WordPress database (wp_posts table) or use a plugin to search post content for the shortcode pattern [rem_video id= or [rem_video list=.
    Affected if Any posts, pages, or custom post types contain the [rem_video shortcode with user-supplied id or list values

You are affected if the Responsive Video Embedder plugin version is 0.1 or lower AND the rem_video shortcode is being used with id or list attributes, AND those attributes are not sanitized in the source code.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

From vendor data
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Upgrade to a patched version of the plugin that implements proper input sanitization using WordPress escaping functions like esc_attr() and esc_url() on the id and list parameters before inserting them into HTML attributes.

Have this fixed Scoped from the published advisory
  • Consultation2.0 h
  • Implementation2.0 h
  • Testing3.0 h
  • Review / QA2.0 h
9.0 hours of engineering $1,570
Get help mitigating

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $2,512.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2026-8877 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.

Get it on GitHub Scan in the browser

References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-8877 in production — separate from our analysis above.

No notes yet

Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.

What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data