# CVE-2026-126559: Semantic MediaWiki stored cross-site scripting in FacetedSearch

Source: https://junglewise.ai/threats/cve-2026-126559-semantic-mediawiki-4-2-0-before-7-4-1-contains-a-stored-cross  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-11-11. Updated: 2026-11-11  
License: CC BY 4.0 with a link back

CVE-2026-126559 · Severity: medium · CVSS 4.8 · Published 2026-11-11

Semantic MediaWiki is an extension for MediaWiki that enables semantic data management and querying. A stored cross-site scripting vulnerability in the FacetedSearch component allows users with schema editing rights to inject malicious scripts that execute for all visitors viewing the search interface, including administrators, potentially leading to account compromise or administrative action manipulation.

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

## Quick answers

**Is CVE-2026-126559 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-126559 being exploited in the wild.

**How severe is CVE-2026-126559?** Medium severity, with a CVSS score of 4.8, published 11 November 2026.

**Which products and versions are affected?** Semantic MediaWiki 4.2.0 before 7.4.1.

**Is there a fix for CVE-2026-126559?** Yes: fixed in 7.4.1. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-126559 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-126559?** Check whether you run Semantic MediaWiki 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 7.4.1

## Technical details

The OptionsBuilder::profiles() method in FacetedSearch interpolates profile keys and labels directly into HTML option elements without proper escaping. An attacker with the smw-schemaedit permission can author a FACETEDSEARCH_PROFILE_SCHEMA containing malicious markup that breaks out of the value attribute and injects JavaScript. The payload persists in the schema configuration and executes for every visitor of Special:FacetedSearch, including administrators.

## Affected products

- Semantic MediaWiki Semantic MediaWiki 4.2.0 before 7.4.1

## Timeline

- 2026-11-11: disclosed

## References

- [https://github.com/SemanticMediaWiki/SemanticMediaWiki/blob/7.4.0/src/MediaWiki/Specials/FacetedSearch/OptionsBuilder.php](https://github.com/SemanticMediaWiki/SemanticMediaWiki/blob/7.4.0/src/MediaWiki/Specials/FacetedSearch/OptionsBuilder.php)
- [https://github.com/SemanticMediaWiki/SemanticMediaWiki/commit/92999fc0de74324aaa35bfd3676cd4d145d2ac06](https://github.com/SemanticMediaWiki/SemanticMediaWiki/commit/92999fc0de74324aaa35bfd3676cd4d145d2ac06)

## Related threats

- [Semantic MediaWiki authorization bypass in edit protection](https://junglewise.ai/threats/cve-2026-126566-semantic-mediawiki-7-3-1-before-7-4-1-contains-an-incorrect)
- [Semantic MediaWiki denial of service in concept expansion](https://junglewise.ai/threats/cve-2026-126565-semantic-mediawiki-3-0-0-before-7-4-1-contains-a-denial-of)
- [Semantic MediaWiki stored XSS in ValueFormatter property label](https://junglewise.ai/threats/cve-2026-126564-semantic-mediawiki-2-5-0-before-7-4-1-contains-a-stored-cross)
- [Semantic MediaWiki uncontrolled recursion in ConceptDescriptionInterpreter](https://junglewise.ai/threats/cve-2026-126562-semantic-mediawiki-3-0-0-before-7-4-1-contains-an-uncontrolled)
- [Semantic MediaWiki missing authorization in page edit protection](https://junglewise.ai/threats/cve-2026-126561-semantic-mediawiki-2-5-0-before-7-4-1-contains-a-missing)