# CVE-2026-116888: SemanticMediaWiki stored XSS in Special:Browse via schema canonical_name

Source: https://junglewise.ai/threats/cve-2026-116888-semanticmediawiki-from-3-2-0-before-7-3-1-contains-a-stored  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-10-27. Updated: 2026-10-27  
License: CC BY 4.0 with a link back

CVE-2026-116888 · Severity: medium · CVSS 4.8 · Published 2026-10-27

SemanticMediaWiki is a MediaWiki extension that adds structured data and semantic searching to wikis. An authenticated user with schema editing privileges can inject malicious script into property group schemas, which then executes in the browsers of other users—including administrators—when they view affected pages. This allows attackers to steal session data or perform actions as the viewing user.

Vendors: [Semantic MediaWiki](https://junglewise.ai/threats/vendors/semantic-mediawiki).

## Quick answers

**Is CVE-2026-116888 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-116888 being exploited in the wild.

**How severe is CVE-2026-116888?** Medium severity, with a CVSS score of 4.8, published 27 October 2026.

**Which products and versions are affected?** Semantic MediaWiki SemanticMediaWiki 3.2.0 before 7.3.1.

**Is there a fix for CVE-2026-116888?** Yes: fixed in 7.3.1. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-116888 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-116888?** Check whether you run Semantic MediaWiki SemanticMediaWiki at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- Fixed in 7.3.1

## Technical details

A stored cross-site scripting vulnerability in GroupFormatter's rendering of Special:Browse page headings. The vulnerability stems from failure to HTML-escape the canonical_name field from property group schemas before inserting it into page headings via unescaped Mustache templates. An attacker with the smw-schemaedit right can create a schema with a canonical_name containing arbitrary markup (e.g., img/script tags), which is validated only by the permissive pattern ^(.*)$ and stored verbatim, then rendered without sanitization when any user views Special:Browse for pages with member properties of that group.

## Affected products

- Semantic MediaWiki SemanticMediaWiki 3.2.0 before 7.3.1

## Timeline

- 2026-09-28: disclosed
- 2026-10-27: advisory

## References

- [https://github.com/SemanticMediaWiki/SemanticMediaWiki/security/advisories/GHSA-fp94-c5vh-cmhp](https://github.com/SemanticMediaWiki/SemanticMediaWiki/security/advisories/GHSA-fp94-c5vh-cmhp)
- [https://www.vulncheck.com/advisories/semanticmediawiki-3.2.0-before-7.3.1-stored-xss-via-special-browse-group-heading](https://www.vulncheck.com/advisories/semanticmediawiki-3.2.0-before-7.3.1-stored-xss-via-special-browse-group-heading)

## Related threats

- [SemanticMediaWiki stored cross-site scripting in Special:Browse](https://junglewise.ai/threats/cve-2026-116889-semanticmediawiki-from-2-5-0-before-7-3-1-contains-a-stored)