CVE-2026-30977: RenderBlocking has Stored XSS in renderblocking-css with Inline Assets mode

Published Mar 10, 2026
·
Updated

RenderBlocking is a MediaWiki extension that allows interface administrators to specify render-blocking CSS and JavaScript. Prior to 0.1.1, there is Stored XSS in renderblocking-css with Inline Assets mode. $wgRenderBlockingInlineAssets = true and editsitecss user rights are required. This vulnerability is fixed in 0.1.1.

Affected Software

1 affected component
MediaWiki RenderBlocking<0.1.1

Event History

Mar 10, 2026
CVE Published
via MITRE·05:40 PM
Data Sourced
via MITRE·05:40 PM
DescriptionWeakness
Data Sourced
via NVD·06:18 PM
DescriptionSeverityWeakness
May 6, 58175
Event
via FIRST·09:51 AM

Frequently Asked Questions

1

What is the severity of CVE-2026-30977?

CVE-2026-30977 is classified as a high severity vulnerability due to its potential for stored cross-site scripting (XSS) attacks.

2

How do I fix CVE-2026-30977?

To fix CVE-2026-30977, upgrade the MediaWiki RenderBlocking extension to version 0.1.1 or later.

3

What is the impact of CVE-2026-30977?

The impact of CVE-2026-30977 allows attackers to inject malicious scripts through stored XSS, compromising the security of users viewing affected pages.

4

Which versions of MediaWiki RenderBlocking are vulnerable to CVE-2026-30977?

Versions of MediaWiki RenderBlocking prior to 0.1.1 are vulnerable to CVE-2026-30977.

5

Who is affected by CVE-2026-30977?

Administrators using MediaWiki with the RenderBlocking extension prior to version 0.1.1 are affected by CVE-2026-30977.

Contact

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