CVE-2026-55692 is a high-severity (CVSS 7.5) Cross-site Scripting (XSS) vulnerability in starcitizenwiki/embedvideo. A fix is available for starcitizenwiki/embedvideo — see the affected versions and patch details below.
EmbedVideo Extension: Stored XSS via malformed src url with $wgEmbedVideoRequireConsent enabled
Exploitation Status
Proof-of-concept exploit code exists
- CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.
- CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
Exploitation and automatability from CISA’s SSVC triage for CVE-2026-55692.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
CVE-2026-55692 by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.
Where this sits among everything scored
Of 394,803 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Counts from FIRST.org, log-scaled.
Real-World Exposure
starcitizenwiki/embedvideoReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Packagist packages — download data is not available via public APIs for these ecosystems.
Description
Summary
With $wgEmbedVideoRequireConsent enabled (the default), the urls for videos are stored in a json-ified data attributedata-mw-iframeconfig. When given a malformed url or id, the data-mw-iframeconfig attribute can be escaped via single quotes, allowing for html/javascript injection.
Details
The sprintf here adds the iframe config encoded as JSON here. When given a malicious url or id with a single quote, the $this->getUrl() call returns an unescaped payload that terminates the data-mw-iframeconfig attribute and allows for injecting attributes, including handlers, into the figure element. The id regex for the archiveorg service and the url regexes for the wistia and sharepoint services allow for single quotes to be introduced.
PoC
A couple of examples across services
Input:
<embedvideo service="archiveorg" id="x' onmouseover='alert(document.domain)' data-x='"></embedvideo>
Renders:
<figure class="embedvideo" data-service="archiveorg" data-mw-iframeconfig="{"src":"//archive.org/embed/x" onmouseover="alert(document.domain)" data-x="?autoplay=1"}" style="width:640px">
<div class="embedvideo-wrapper" style="height:493px"><div class="embedvideo-consent" data-show-privacy-notice="1">
...
</div>
</figure>
Input:
{{#ev:wistia|https://wistia.com/medias/x'onmouseover='alert(document.domain)'}}
Renders:
<figure class="embedvideo" data-service="wistia" data-mw-iframeconfig="{"src":"//fast.wistia.net/embed/iframe/x" onmouseover="alert(document.domain)" ?autoplay="1"}'" style="width:640px">
<div class="embedvideo-wrapper" style="height:360px"><div class="embedvideo-consent" data-show-privacy-notice="1">
...
</div>
</figure>
{{#ev:sharepoint|https://a.sharepoint.com/sites/x'onmouseover='alert(document.domain)'.aspx}}
Impact
Under the default $wgEmbedVideoRequireConsent = true configuration, any user able to edit a page can inject arbitrary JavaScript into an HTML event handler attribute (e.g. onfocus) via parameter. It requires no interaction (autofires via autofocus) and executes in the wiki origin for every visitor to the page.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐘Packagist | starcitizenwiki/embedvideo | all versions | 4.1.0composer require starcitizenwiki/embedvideo:^4.1.0 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for starcitizenwiki/embedvideo, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update starcitizenwiki/embedvideo to 4.1.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-55692 is resolved across your whole dependency graph.
Workarounds
Escape or sanitise the affected output on the server side rather than relying on client-side filtering, and add a Content-Security-Policy that blocks inline script execution so injected markup cannot run even if it reaches the page.
Frequently Asked Questions
Is CVE-2026-55692 in your dependencies?
Find it across Packagist, including transitive dependencies.