---
id: "CVE-2026-126565"
page: "https://infrastack.ai/live/CVE-2026-126565"
kind: "vulnerability"
aliases: ["CVE-2026-126565"]
title: "Semantic MediaWiki: users with edit rights can exhaust server CPU and memory"
severity: "medium"
cvss: 5.3
epss: null
exploited: false
status: "open"
category: "package"
products: []
ecosystems: []
tags: ["mediawiki", "package", "self-hosted", "semantic-mediawiki"]
not_affected_if: ["auth-required", "default-store"]
published_at: "2026-11-11T03:16:50+00:00"
first_seen_at: "2026-11-11T03:25:00+00:00"
updated_at: "2026-11-11T03:26:31+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-126565", "first_seen_at": "2026-11-11T03:25:00+00:00"}]
exploit_sources: []
---

# Semantic MediaWiki: users with edit rights can exhaust server CPU and memory

Link for people: https://infrastack.ai/live/CVE-2026-126565 (this .md is for agents)

Semantic MediaWiki's ElasticStore and SPARQLStore re-expand concept pages without limits, so a chain of Concept pages fans out. A user with page-edit rights can make queries exhaust CPU and memory, causing denial of service.

_Summary, check and fix written by a model from the sources; labelled as such._

## How to check

- Check the installed Semantic MediaWiki version in Special:Version or `composer show mediawiki/semantic-media-wiki`
- Check whether the wiki uses the ElasticStore or SPARQLStore backend (unknown otherwise)

## Fix

- Semantic MediaWiki: move to `7.4.1` or later (per the NVD range, versions before 7.4.1 from 3.0.0 are affected)

## Timeline

- 2026-11-11T03:25:00+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-126565

## Documents

- [advisory] Vendor advisory: github.com https://github.com/SemanticMediaWiki/SemanticMediaWiki/security/advisories/GHSA-24v2-mf3g-84ch
- [advisory] Third-party advisory: www.vulncheck.com https://www.vulncheck.com/advisories/semantic-mediawiki-3.0.0-before-7.4.1-dos-via-exponential-concept-expansion
- [fix] Patch: github.com https://github.com/SemanticMediaWiki/SemanticMediaWiki/commit/86ce13254ffd91406ef43ea403ae072a7e3a38b3
- [fix] Release notes: github.com https://github.com/SemanticMediaWiki/SemanticMediaWiki/releases/tag/7.4.1

## From the sources

Semantic MediaWiki 3.0.0 before 7.4.1 contains a denial of service vulnerability in the ElasticStore and SPARQLStore ConceptDescriptionInterpreter classes, which re-expand concepts without memoization or an expansion budget. Users with page-edit rights can build acyclic chains of Concept: pages that fan out, so queries via concept page views, Special:Ask, or api.php action=ask exhaust CPU and memory.

---

_Free to read, with fair use of about 60 pages a minute. For higher limits or API access: sales@infrastack.ai_