CVE-2026-116871
Received Received - Intake

Uncontrolled Recursion in Semantic MediaWiki

Publication date: 2026-10-27

Last updated on: 2026-10-27

Assigner: VulnCheck

Description
Semantic MediaWiki 3.0.0 before 7.3.1 contains an uncontrolled recursion vulnerability in LegacyParser::getSubqueryDescription() that processes nested query tokens before depth limits apply. Unauthenticated attackers can submit deeply nested query elements to the action=ask API to consume substantial CPU and memory, tying up request workers.

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Meta Information

Published
2026-10-27
Last Modified
2026-10-27
Generated
2026-10-27
AI Q&A
2026-10-27
EPSS Evaluated
N/A
NVD
CVE-2026-116871
EUVD
EUVD-2026-110699

Affected Vendors & Products

Showing 1 associated CPE
Vendor Product Version / Range
SemanticMediaWiki SemanticMediaWiki 3.0.0

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Exploitability

CWE
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KEV
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CWE ID Description
CWE-674 The product does not properly control the amount of recursion that takes place, consuming excessive resources, such as allocated memory or the program stack.

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Executive Summary

This vulnerability is an uncontrolled recursion flaw in Semantic MediaWiki versions 3.0.0 through 7.3.0. It occurs in the LegacyParser::getSubqueryDescription() function, which processes nested query tokens without proper depth limits. Attackers can exploit this by submitting deeply nested queries to the action=ask API, causing excessive CPU and memory consumption.

Detection Guidance

To detect this vulnerability, monitor for unusually high CPU or memory usage on your Semantic MediaWiki server, particularly when processing requests to the action=ask API. Check for excessive recursion errors in logs or network traffic analysis tools. The vulnerability may manifest as slow response times or system unresponsiveness during query processing.

Impact Analysis

Unauthenticated attackers can send deeply nested queries to consume significant server resources, tying up request workers. This may lead to service degradation or denial of service, affecting availability for legitimate users.

Mitigation Strategies

Immediately upgrade Semantic MediaWiki to version 7.3.1 or later, which includes fixes for the uncontrolled recursion issue. If upgrading is not immediately possible, implement network-level protections such as rate limiting or blocking large POST requests to the action=ask API endpoint. Temporarily disable the action=ask API if it is not essential.

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