How severe is GHSA-4x6x-8rm8-c37j?

GHSA-4x6x-8rm8-c37j has a CVSS score of 8.6/10, rated HIGH. Immediate patching is strongly recommended.

Which packages are affected by GHSA-4x6x-8rm8-c37j?

GHSA-4x6x-8rm8-c37j affects the following packages: starcitizentools/tabber-neue (Packagist). Ecosystems affected: Packagist.

How do I fix GHSA-4x6x-8rm8-c37j?

Update starcitizentools/tabber-neue to 2.7.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-4x6x-8rm8-c37j is resolved across your whole dependency graph.

How do I detect GHSA-4x6x-8rm8-c37j in my Packagist dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for starcitizentools/tabber-neue. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.

How do I mitigate GHSA-4x6x-8rm8-c37j if there is no patch (or I can't update yet)?

If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

How does O3 Security protect against GHSA-4x6x-8rm8-c37j?

O3 pinpoints whether GHSA-4x6x-8rm8-c37j is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Is GHSA-4x6x-8rm8-c37j actively exploited in the wild?

No public exploit code has been indexed for GHSA-4x6x-8rm8-c37j yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for GHSA-4x6x-8rm8-c37j?

GHSA-4x6x-8rm8-c37j has an EPSS (Exploit Prediction Scoring System) score of 0.5%, placing it in the 38th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is GHSA-4x6x-8rm8-c37j?

GHSA-4x6x-8rm8-c37j is classified as Cross-site Scripting (XSS) (CWE-79), CWE-80 (CWE-80). These weakness types describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation. This is a high-impact weakness class that often enables remote code execution or data exposure.

When was GHSA-4x6x-8rm8-c37j published, and has it been updated?

GHSA-4x6x-8rm8-c37j was published on January 6, 2025 and was last updated on January 6, 2025. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

🐘 Packagist

GHSA-4x6x-8rm8-c37j

HIGH

Extension:TabberNeue vulnerable to Cross-site Scripting

Also known asCVE-2025-21612

Published

Jan 6, 2025

Updated

Jan 6, 2025

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

EPSS Exploitation Probability

via FIRST.org ↗

0.5%probability of exploitation in next 30 days

Lower Risk38th percentile+0.23%

EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.

Blast Radius

1 pkg affected

🐘starcitizentools/tabber-neue

Real-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

There are several sources of arbitrary, unescaped user input being used to construct HTML, which allows any user that can edit pages or otherwise render wikitext to XSS other users.

Edit: Only the first XSS can be reproduced in production.

Details

✅ Verified and patched in f229cab099c69006e25d4bad3579954e481dc566

https://github.com/StarCitizenTools/mediawiki-extensions-TabberNeue/blob/2526daa9f8cfdd616c861c8439755cb74a6c8c6e/includes/TabberTransclude.php#L154 This doesn't escape the user-supplied page name when outputting, so an XSS payload as the page name can be used here.

This was caused by d8c3db4e5935476e496d979fb01f775d3d3282e6.

❌ Invalid as MediaWiki parser sanitizes dangerous HTML

https://github.com/StarCitizenTools/mediawiki-extensions-TabberNeue/blob/2526daa9f8cfdd616c861c8439755cb74a6c8c6e/includes/Tabber.php#L160 The documentation for Parser::recursiveTagParse() states that it returns unsafe HTML, and the $content being supplied is from user input.

This was caused by 95351812613e04717f3ad7844cfcc67e4ede4d11.

❌ Invalid as TabberParsoid is not being used

https://github.com/StarCitizenTools/mediawiki-extensions-TabberNeue/blob/2526daa9f8cfdd616c861c8439755cb74a6c8c6e/includes/TabberParsoid.php#L96 This uses unescaped user input as the attribute of an element, thus allowing the user to break out of the attribute or element and injecting arbitrary attributes to the element, or inserting new ones (such as a script tag).

This was caused by 8278e665480f08da635aee383c6b5caaeca26ba3.

PoC

For the first XSS, render the following wikitext (whether it be through saving it to a page and viewing it, or via Special:ExpandTemplates):

<tabbertransclude>
<script>alert(1)</script> | hehe
</tabbertransclude>

For the second XSS, I have given up attempting to reproduce it after over twenty minutes of "surfing through the internals of the MediaWiki parser fishing for an XSS out of this giant contraption as I bring myself deeper and deeper into the cogs of the machine that no one knows how to maintain or fully operate ever since its conception".

For the third XSS, this is unreachable as the class is never used, though it should be fixed anyway (or the file removed).

Impact

Any user with the ability to cause another user to render wikitext (such as viewing a page that the user can edit, or an attacker tricking the victim to click on a link to Special:ExpandTemplates with the malicious wikitext in the wpInput parameter) can XSS said user.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
🐘Packagist	`starcitizentools/tabber-neue`	≥ 1.9.1&&< 2.7.2	2.7.2

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for starcitizentools/tabber-neue. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update starcitizentools/tabber-neue to 2.7.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-4x6x-8rm8-c37j is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether GHSA-4x6x-8rm8-c37j is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Tailored to GHSA-4x6x-8rm8-c37j. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

### Summary There are several sources of arbitrary, unescaped user input being used to construct HTML, which allows any user that can edit pages or otherwise render wikitext to XSS other users. > Edit: Only the first XSS can be reproduced in production. ### Details > ✅ Verified and patched in f229cab099c69006e25d4bad3579954e481dc566 https://github.com/StarCitizenTools/mediawiki-extensions-TabberNeue/blob/2526daa9f8cfdd616c861c8439755cb74a6c8c6e/includes/TabberTransclude.php#L154 This doesn't escape the user-supplied page name when outputting, so an XSS payload as the page name can be used

O3 Security · Impact-Aware SCA

Is GHSA-4x6x-8rm8-c37j in your dependencies?

O3 detects GHSA-4x6x-8rm8-c37j across Packagist dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.

Scan my dependencies How O3 SCA works