CVE-2026-55690: Starcitizenwiki/embedvideo Cross-Site Scripting Vulnerability
HIGHCVE-2026-55690 is a HIGH (CVSS 7.5) cross-site scripting vulnerability (CWE-80: Improper Neutralization of Script-Related HTML Tags in a Web Page (Basic XSS)) affecting Starcitizenwiki/embedvideo libraries in the Packagist ecosystem. The issue involves stored xss via unsanitized service name in exception text. Remediation is available by upgrading affected packages to version 4.1.0.
CVE-2026-55690 at a Glance
Security Impact
CVSS: 7.5
The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N).
How to Fix CVE-2026-55690
To remediate this vulnerability, upgrade all affected Starcitizenwiki/embedvideo dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.
Upgrade starcitizenwiki/embedvideo to 4.1.0Run the following command in your project directory to verify that all resolved dependencies use the patched release:
inspect dependencies for starcitizenwiki/embedvideoHow to Check if You Are Affected
To determine whether your application is affected by CVE-2026-55690, inspect your project dependencies for Starcitizenwiki/embedvideo:
inspect dependencies for starcitizenwiki/embedvideoAnalyze the terminal output to locate any version of Starcitizenwiki/embedvideo in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 4.1.0), your application is affected.
Note: Verify declared build manifests and deployed runtime container environments.
Technical Details
Vulnerability Mechanism & Technical Analysis
This vulnerability is classified under CWE-80: Improper Neutralization of Script-Related HTML Tags in a Web Page (Basic XSS), where the product receives input from an upstream component, but it does not neutralize or incorrectly neutralizes special characters such as "<", ">", and "&" that could be interpreted as web-scripting elements when they are sent to a downstream component that processes web pages. In Starcitizenwiki/embedvideo, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.
Source Advisory Statement
CVE-2026-55690 Affected Starcitizenwiki/embedvideo Versions
1 component(s)| Product / Package | Ecosystem | Affected Versions | Fixed Version |
|---|---|---|---|
|
starcitizenwiki/embedvideo
|
Packagist |
< 4.1.0
|
4.1.0
|
References
Frequently Asked Questions
What is CVE-2026-55690?
Which Starcitizenwiki/embedvideo versions are affected?
What version fixes CVE-2026-55690?
Is starcitizenwiki/embedvideo affected?
What is the CVSS score of CVE-2026-55690?
What CWE is associated with CVE-2026-55690?
How can I check Packagist dependencies for CVE-2026-55690?
Machine-readable OSV JSON
OSV v1.5 Schema
{
"schema_version" : "1.4.0",
"id" : "GHSA-c29q-5xm7-5p62",
"modified" : "2026-06-19T21:14:15Z",
"published" : "2026-06-19T21:14:15Z",
"aliases" : [ "CVE-2026-55690" ],
"summary" : "StarCitizenWiki Extension Embed Video: Stored XSS via unsanitized service name in exception text",
"details" : "### Summary\nWhen passing an unknown service name to embedvideo, an error message is rendered containing the invalid service name. The service name is not sanitized and can contain HTML.\n\n### Details\nThere is a hardcoded list of allowed services in a switch statement inside `EmbedServiceFactory#newFromName` [here](https://github.com/StarCitizenWiki/mediawiki-extensions-EmbedVideo/blob/a573a16d925ee0ea0d34b360856dc8ab0b88f822/includes/EmbedService/EmbedServiceFactory.php#L105). When the service name is not known, an exception is thrown with the service name injected into the message via sprintf [here](https://github.com/StarCitizenWiki/mediawiki-extensions-EmbedVideo/blob/a573a16d925ee0ea0d34b360856dc8ab0b88f822/includes/EmbedService/EmbedServiceFactory.php#L286). This message is not sanitized and is marked as isHtml [here](https://github.com/StarCitizenWiki/mediawiki-extensions-EmbedVideo/blob/a573a16d925ee0ea0d34b360856dc8ab0b88f822/includes/EmbedVideo.php#L303-L311). Similarly with `{{evl:` [here](https://github.com/StarCitizenWiki/mediawiki-extensions-EmbedVideo/blob/a573a16d925ee0ea0d34b360856dc8ab0b88f822/includes/EmbedVideo.php#L177-L183).\n\n### PoC\n```\n// Must be on a page, not on ExpandTemplates\n{{#ev:<img src=x onerror=alert(document.domain)>|dQw4w9WgXcQ}}\n{{#evl:id=dummy|service=<img src=x onerror=alert(document.domain)>}}\n```\n\n### Impact\nStored XSS that allows arbitrary Javascript/HTML insertion on any page that a user can edit. It requires no interaction and executes in the wiki origin for every visitor to the page.",
"severity" : [ {
"type" : "CVSS_V3",
"score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N"
} ],
"affected" : [ {
"package" : {
"ecosystem" : "Packagist",
"name" : "starcitizenwiki/embedvideo"
},
"ranges" : [ {
"type" : "ECOSYSTEM",
"events" : [ {
"introduced" : "0"
}, {
"fixed" : "4.1.0"
} ]
} ],
"database_specific" : {
"last_known_affected_version_range" : "<= 4.0.0"
}
} ],
"references" : [ {
"type" : "WEB",
"url" : "https://github.com/StarCitizenWiki/mediawiki-extensions-EmbedVideo/security/advisories/GHSA-c29q-5xm7-5p62"
}, {
"type" : "WEB",
"url" : "https://github.com/StarCitizenWiki/mediawiki-extensions-EmbedVideo/commit/9215564bf28a0ceb40be550a55ab78efc0accc56"
}, {
"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"
} ],
"database_specific" : {
"cwe_ids" : [ "CWE-79", "CWE-80" ],
"severity" : "HIGH",
"github_reviewed" : true,
"github_reviewed_at" : "2026-06-19T21:14:15Z",
"nvd_published_at" : null
}
}