---
id: "CVE-2026-116891"
kind: "vulnerability"
aliases: ["CVE-2026-116891"]
title: "SemanticMediaWiki: reflected XSS in FacetedSearch via cstate parameter"
severity: "medium"
cvss: 6.1
epss: null
exploited: false
status: "open"
category: "package"
products: []
ecosystems: []
tags: ["mediawiki", "package", "self-hosted", "semantic-mediawiki"]
not_affected_if: ["version-outside-range"]
published_at: "2026-10-27T11:17:31+00:00"
first_seen_at: "2026-10-27T11:31:27+00:00"
updated_at: "2026-10-27T11:32:01+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-116891", "first_seen_at": "2026-10-27T11:31:27+00:00"}]
---

# SemanticMediaWiki: reflected XSS in FacetedSearch via cstate parameter

SemanticMediaWiki versions 4.2.0 through 7.2.0 do not escape the cstate parameter on Special:FacetedSearch, so crafted URLs inject HTML. An unauthenticated attacker who gets a victim to open such a link can run script in the victim's browser.

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

## How to check

- Check the installed SemanticMediaWiki version in the wiki's Special:Version page or the extension's composer or extension.json metadata
- Look for the Special:FacetedSearch page being used with a cstate parameter

## Fix

- Upgrade SemanticMediaWiki to `7.2.1` or later

## Timeline

- 2026-10-27T11:31:27+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-116891

## From the sources

SemanticMediaWiki from 4.2.0 before 7.2.1 contains a reflected cross-site scripting vulnerability that allows unauthenticated attackers to inject HTML via unescaped cstate parameters in Special:FacetedSearch. Attackers can craft URLs with q, a matching crc32 csum or filtered=1, and cstate values that break out of hidden input attributes to execute script in victims' browsers.

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_Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai_