fixnx
infoCVE-2026-58035

CVE-2026-58035 in MediaWiki

Improper Neutralization of Input During Web Page Generation (XSS or 'Cross-site Scripting') vulnerability in Wikimedia Foundation MediaWiki. This vulnerability is associated with program files resources/src/mediawiki.Special.Block/SpecialBlock.Vue.

ProductMediaWiki
Risk levelInfo
EPSS0.00142
UpdatedJuly 15, 2026

Quick answer

Wikimedia Foundation MediaWiki should be reviewed and updated if it matches the affected versions. The recommended fix is to apply the vendor-supported patched version or the mitigation steps below, then retest the public website with Fixnx.

Who is affected

Affected versions

  • MediaWiki 1.46.0-rc.0 before 1.46.0
  • 1.46.0

Fixed versions

  • MediaWiki 1.46.0 or later

How to fix it

CVE-2026-58035 affects MediaWiki. Update MediaWiki or the affected extension to a supported fixed branch. Keep editing and admin access limited until the update is live.

  1. Find the MediaWiki site or extension that uses MediaWiki.
  2. Check if it matches MediaWiki 1.46.0-rc.0 before 1.46.0.
  3. Update to MediaWiki 1.46.0 or later.
  4. Back up the site and database before changing code.
  5. Clear caches after the update.
  6. Review logs for strange account, page, or admin activity.
  7. Remove old extension files that are no longer used.

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Verify the fix

  • Confirm the fixed MediaWiki or extension version is deployed.
  • Test login, edit, and admin flows.
  • Check that the issue cannot be repeated.
  • Run a new Fixnx scan.
  • Keep the Wikimedia or NVD advisory in the change record.

Related categories

PHPWeb ApplicationCross-site Scripting

Trusted references

Source advisoryNVDSource advisoryNVDSource advisoryNVD

FAQ

What is affected by CVE-2026-58035?

Wikimedia Foundation MediaWiki versions listed as affected should be reviewed: MediaWiki 1.46.0-rc.0 before 1.46.0, 1.46.0.

What should I fix first?

Start with internet-facing sites, admin panels, login flows, plugins, themes, modules, packages, and systems that process user-controlled input or sensitive data.

How do I confirm the fix worked?

Apply the patched version or mitigation, clear caches where relevant, retest the affected workflow, and run a new Fixnx scan to verify public website exposure signals.

How are Fixnx security risk categories chosen?

Fixnx keeps one canonical risk page and assigns only broad, relevant categories such as ecosystem, technology area, or vulnerability class.