Semantic MediaWiki has reflected XSS in Special:Ask plain table headers — GHSA-3JP5-3H47-28QF

Summary

#### Failure mode When `headers=plain`, table header text was emitted into `<th>` via a raw HTML path. User-controlled `mainlabel` content could therefore become executable HTML. #### Remediation - `TableResultPrinter` now applies output-context escaping before passing plain headers to the table renderer. - The fix is limited to the HTML/plain-header branch so safe rendering modes are unaffected. #### Why this is…

Timeline

Published by source

2026-09-18

Risk context

• Reported severity or threat level: medium.
• Reported CVSS score: 6.1 out of 10.
• Review exposure for the affected product or family: composer: mediawiki/semantic-media-wiki.

Product

composer: mediawiki/semantic-media-wiki

What to do

General, cautious steps (verify details in the official source):

• Review exposure and plan remediation based on risk and environment.
• Identify affected product versions in your inventory and verify whether you are impacted.
• Apply vendor patches/updates or recommended mitigations as soon as available.
• Read the official advisory for exact affected versions and remediation steps.

Official advisory

• Read the official source
• CVE Record
• NVD

Evidence and provenance

Canonical advisory ID

GHSA-3JP5-3H47-28QF

Source

GitHub

Vendor

GitHub

Published by source

2026-09-18

Last source activity

2026-09-18

Additional identifiers

CVE-2026-77606

Curated by

hlukh.ch

Related advisories and connections

These advisories are connected by shared CVE, product, vendor, source, or time signals.