Semantic MediaWiki 3.0.0 before 7.4.1 DoS via Exponential Concept Expansion

Advisories

Semantic MediaWiki 3.0.0 before 7.4.1 DoS via Exponential Concept Expansion

Severity: medium
Date: 11/10/2026
Affecting: SemanticMediaWiki >= 3.0.0, < 7.4.1
CVE: CVE-2026-126565
CWE: CWE-407 Inefficient Algorithmic Complexity
CVSS: 5.3
CVSS V4 Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N
References: GitHub Security Advisory (GHSA-24v2-mf3g-84ch)
https://github.com/SemanticMediaWiki/SemanticMediaWiki/commit/86ce13254ffd91406ef43ea403ae072a7e3a38b3
SemanticMediaWiki 7.4.1 Release Notes
https://github.com/SemanticMediaWiki/SemanticMediaWiki/blob/7.4.0/src/Elastic/QueryEngine/DescriptionInterpreters/ConceptDescriptionInterpreter.php#L34-L75
https://github.com/SemanticMediaWiki/SemanticMediaWiki/blob/7.4.0/src/SPARQLStore/QueryEngine/DescriptionInterpreters/ConceptDescriptionInterpreter.php#L49-L105
Credit: AlpetGexha
Description: 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.

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