GHSA-7H5P-637F-JFR7
Vulnerability from github – Published: 2026-06-19 21:15 – Updated: 2026-06-19 21:15
VLAI
Summary
StarCitizenWiki Extension Embed Video: Stored XSS via unsanitized class passed to template
Details
Summary
The user supplied class value is fed directly into the sprintf call that creates HTML. You can add a quote to escape the class and then inject arbitrary html/javascript to the final output.
Details
The template here adds a figure with a class that is substituted in. This value is provided to sprintf here, an unescaped version of the class supplied by the user.
$template = <<<HTML
<figure class="%s" data-service="%s" %s %s>
<div class="embedvideo-wrapper" %s>%s%s%s</div>%s
</figure>
HTML;
PoC
Note the double quote immediately following the single quote to escape the class attribute in the template:
<youtube class='" onmouseover="alert(document.domain)' id="dQw4w9WgXcQ">dQw4w9WgXcQ</youtube>
Impact
Arbitrary HTML can be inserted into the DOM by any user on any page, allowing for JavaScript to be executed.
Severity
8.6 (High)
{
"affected": [
{
"database_specific": {
"last_known_affected_version_range": "\u003c= 4.0.0"
},
"package": {
"ecosystem": "Packagist",
"name": "starcitizenwiki/embedvideo"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "4.1.0"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2026-55691"
],
"database_specific": {
"cwe_ids": [
"CWE-79",
"CWE-80"
],
"github_reviewed": true,
"github_reviewed_at": "2026-06-19T21:15:03Z",
"nvd_published_at": null,
"severity": "HIGH"
},
"details": "### Summary\nThe user supplied class value is fed directly into the sprintf call that creates HTML. You can add a quote to escape the class and then inject arbitrary html/javascript to the final output.\n\n### Details\nThe template [here](https://github.com/StarCitizenWiki/mediawiki-extensions-EmbedVideo/blob/a573a16d925ee0ea0d34b360856dc8ab0b88f822/includes/EmbedService/EmbedHtmlFormatter.php#L138) adds a figure with a class that is substituted in. This value is provided to sprintf [here](https://github.com/StarCitizenWiki/mediawiki-extensions-EmbedVideo/blob/a573a16d925ee0ea0d34b360856dc8ab0b88f822/includes/EmbedService/EmbedHtmlFormatter.php#L156), an unescaped version of the class supplied by the user.\n\n```\n$template = \u003c\u003c\u003cHTML\n \u003cfigure class=\"%s\" data-service=\"%s\" %s %s\u003e\n \u003cdiv class=\"embedvideo-wrapper\" %s\u003e%s%s%s\u003c/div\u003e%s\n \u003c/figure\u003e\nHTML;\n```\n\n### PoC\nNote the double quote immediately following the single quote to escape the class attribute in the template:\n```\n\u003cyoutube class=\u0027\" onmouseover=\"alert(document.domain)\u0027 id=\"dQw4w9WgXcQ\"\u003edQw4w9WgXcQ\u003c/youtube\u003e\n```\n\n### Impact\nArbitrary HTML can be inserted into the DOM by any user on any page, allowing for JavaScript to be executed.",
"id": "GHSA-7h5p-637f-jfr7",
"modified": "2026-06-19T21:15:03Z",
"published": "2026-06-19T21:15:03Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/StarCitizenWiki/mediawiki-extensions-EmbedVideo/security/advisories/GHSA-7h5p-637f-jfr7"
},
{
"type": "WEB",
"url": "https://github.com/StarCitizenWiki/mediawiki-extensions-EmbedVideo/commit/370156335b325bb81d14d89edf0a1f2643d50a84"
},
{
"type": "PACKAGE",
"url": "https://github.com/StarCitizenWiki/mediawiki-extensions-EmbedVideo"
},
{
"type": "WEB",
"url": "https://github.com/StarCitizenWiki/mediawiki-extensions-EmbedVideo/releases/tag/v4.1.0"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:L",
"type": "CVSS_V3"
}
],
"summary": "StarCitizenWiki Extension Embed Video: Stored XSS via unsanitized class passed to template"
}
Loading…
Loading…
Experimental. This forecast is provided for visualization only and may change without notice. Do not use it for operational decisions.
Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
Loading…
The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the
vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base
model, served locally by ML-Gateway.
They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.
Loading…
Related by attack behaviour
Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.
Loading…