CVE-2026-126565 json
Semantic MediaWiki 3.0.0 before 7.4.1 DoS via Exponential Concept Expansion
published yesterday modified yesterday also EUVD-2026-123080 , GHSA-24v2-mf3g-84ch
Unreviewed: the maintainers' own advisory
Published by the maintainers on their GitHub repository SemanticMediaWiki/SemanticMediaWiki. GitHub has not reviewed it into the GitHub Advisory Database, so the affected packages and versions are the maintainers' word. Read the full advisory on GitHub.
- cvss
- 4.3
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.4%
- EPSS 0.4% chance of exploitation in 30 days, percentile 32%
- public exploits
- 0
- none known
Summary
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.
Patch / fix
- SemanticMediaWiki SemanticMediaWiki 7.4.1
Is CVE-2026-126565 in your stack? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.
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0.38% chance of exploitation in the next 30 days, higher than 32% of all scored CVEs (FIRST EPSS, 2026-11-11).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 4.0 | 5.3 | 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 |
| CNA | 3.1 | 4.3 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L |
| CNA | 4.0 | 5.3 | 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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X |
| NVD | 3.1 | 4.3 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L |
Affected products
- SemanticMediaWiki SemanticMediaWiki
Classification
- Weakness
-
- CWE-407 Inefficient Algorithmic Complexity
References
-
github.com
/SemanticMediaWiki/SemanticMediaWiki/commit/86ce13254ffd91406ef43ea403ae072a7e3a38b3
patch
-
github.com
/SemanticMediaWiki/SemanticMediaWiki/security/advisories/GHSA-24v2-mf3g-84ch
vendor-advisory, advisory
-
github.com
/SemanticMediaWiki/SemanticMediaWiki/releases/tag/7.4.1
release-notes
-
github.com
/SemanticMediaWiki/SemanticMediaWiki/blob/7.4.0/src/Elastic/QueryEngine/DescriptionInterpreters/ConceptDescrip
technical-description
-
github.com
/SemanticMediaWiki/SemanticMediaWiki/blob/7.4.0/src/SPARQLStore/QueryEngine/DescriptionInterpreters/ConceptDes
technical-description
-
vulncheck.com
/advisories/semantic-mediawiki-3.0.0-before-7.4.1-dos-via-exponential-concept-expansion
third-party-advisory
Sources
- CVE List CVE-2026-126565
- NVD CVE-2026-126565
- Maintainer advisory GHSA-24v2-mf3g-84ch
Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.
The maintainers of SemanticMediaWiki/SemanticMediaWiki published their own advisory on GitHub. Reviewed sources take precedence over it.