# CVE-2026-126562: Semantic MediaWiki uncontrolled recursion in ConceptDescriptionInterpreter

Source: https://junglewise.ai/threats/cve-2026-126562-semantic-mediawiki-3-0-0-before-7-4-1-contains-an-uncontrolled  
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-2026-126562 · Severity: medium · CVSS 4.3 · Published 2026-11-11

Semantic MediaWiki is a knowledge base extension for Wikipedia. Users with page-edit rights can create mutually referencing concept pages, causing searches and queries to crash the server by exhausting PHP memory or stack space.

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

## Quick answers

**Is CVE-2026-126562 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-126562 being exploited in the wild.

**How severe is CVE-2026-126562?** Medium severity, with a CVSS score of 4.3, published 11 November 2026.

**Which products and versions are affected?** Semantic MediaWiki 3.0.0 before 7.4.1.

**Is there a fix for CVE-2026-126562?** 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-2026-126562 attacked?** It is attacked over the network.

**Am I affected by CVE-2026-126562?** 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

An uncontrolled recursion vulnerability exists in the ElasticStore ConceptDescriptionInterpreter component, which only detects directly self-referencing concepts but fails to prevent mutually or transitively referencing concepts (A→B→A). Attackers with page-edit rights can trigger the vulnerability via concept page views, Special:Ask queries, or api.php action=ask requests. The fix tracks active concepts during expansion to detect and break cycles.

## Affected products

- Semantic MediaWiki Semantic MediaWiki 3.0.0 before 7.4.1

## Timeline

- 2026-11-11: disclosed

## References

- [https://github.com/SemanticMediaWiki/SemanticMediaWiki/blob/7.4.0/src/Elastic/QueryEngine/DescriptionInterpreters/ConceptDescriptionInterpreter.php](https://github.com/SemanticMediaWiki/SemanticMediaWiki/blob/7.4.0/src/Elastic/QueryEngine/DescriptionInterpreters/ConceptDescriptionInterpreter.php)
- [https://github.com/SemanticMediaWiki/SemanticMediaWiki/commit/35d8f8c9c7b48a476751ca0b795b78b648756828](https://github.com/SemanticMediaWiki/SemanticMediaWiki/commit/35d8f8c9c7b48a476751ca0b795b78b648756828)

## 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 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)
- [Semantic MediaWiki stored cross-site scripting in DataTables](https://junglewise.ai/threats/cve-2026-126560-semantic-mediawiki-3-0-0-before-7-4-1-contains-a-stored-cross)