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GHSA-jfj7-249r-7j2m

HighCVSS 8.6 / 10
Published Jun 27, 2025·Last modified Jun 27, 2025
Affected Components(0)

No affected components available

Description

Summary

Arbitrary HTML can be inserted into the DOM by inserting a payload into any allowed attribute of the <tabber> tag.

Details

The args provided within the wikitext as attributes to the <tabber> tag are passed to the TabberComponentTabs class: https://github.com/StarCitizenTools/mediawiki-extensions-TabberNeue/blob/3a23b703ce36cfc4128e7921841f68230be4059a/includes/Tabber.php#L76

In TabberComponentTabs, the attributes are validated before being supplied to the Tabs template. https://github.com/StarCitizenTools/mediawiki-extensions-TabberNeue/blob/3a23b703ce36cfc4128e7921841f68230be4059a/includes/Components/TabberComponentTabs.php#L15-L31 However, the validation is insufficient. What Sanitizer::validateTagAttributes does is call validateAttributes, which

	 * - Discards attributes not on the given list
	 * - Unsafe style attributes are discarded
	 * - Invalid id attributes are re-encoded

However, the attribute values are expected to be escaped when inserted into HTML.

The attribute values are then inserted into HTML without being escaped: https://github.com/StarCitizenTools/mediawiki-extensions-TabberNeue/blob/3a23b703ce36cfc4128e7921841f68230be4059a/includes/templates/Tabs.mustache#L1

PoC

XSS through attributes:

  1. Go to Special:ExpandTemplates and insert the following wikitext:
<tabber class='test123" onmouseenter="alert(1)"'>
|-|First Tab Title=
First tab content goes here.
</tabber>
  1. Press "OK"
  2. Hover over the tabber

image

XSS through script tags:

  1. Go to Special:ExpandTemplates and insert the following wikitext:
<tabber class='test123"&gt;&lt;script&gt;alert(2)&lt;/script&gt;'>
|-|First Tab Title=
First tab content goes here.
</tabber>
  1. Press "OK" image

Impact

Arbitrary HTML can be inserted into the DOM by any user, allowing for JavaScript to be executed.

Risk Scores
Base Score
8.6

The vulnerability can be exploited over the network without needing physical access. It is easy for an attacker to exploit this vulnerability. An attacker does not need any special privileges or access rights. No user interaction is needed for the attacker to exploit this vulnerability. The impact is confined to the system where the vulnerability exists. There is a high impact on the confidentiality of the information. There is a low impact on the integrity of the data. There is a low impact on the availability of the system.

Threat Intelligence
7.9

Exploitation activity has been observed. Apply available patches or mitigations urgently.

EPSS
0.35%

The exploit probability is very low. The vulnerability is unlikely to be exploited in the next 30 days.

Exploit
Not available

We did not find any exploit available. Neither in GitHub repositories nor in the Exploit-Database.

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High severity
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