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


- **Severity:** Medium 5.1 (`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`)
- **Exploited in the wild:** Not known
- **Fix available:** No
- **Published:** 27 Oct 2026
- **Updated:** 27 Oct 2026
- **Also known as:** GHSA-8x9p-9f27-hxfj, GHSA-9rcc-pmj8-ffhr

## What is CVE-2026-116891?

CVE-2026-116891 is a medium-severity vulnerability in SemanticMediaWiki, published on 27 Oct 2026. 

### Official 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.

Weakness: CWE-79 (Improper Neutralization of Input During Web Page Generation)

## Which versions are affected by CVE-2026-116891?

2 open source packages ship an affected version, including mediawiki/semantic-media-wiki. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `mediawiki/semantic-media-wiki` | Packagist | From 4.2.0 | 7.2.1 |
| `mediawiki/semantic-media-wiki` | Packagist | From 4.2.0 | 7.2.1 |

Products: Semantic-Mediawiki Semantic Mediawiki.

## How do I fix CVE-2026-116891?

Upgrade mediawiki/semantic-media-wiki to 7.2.1 or later.

## Is CVE-2026-116891 being exploited?

There is no known exploitation of CVE-2026-116891 in the wild and no public exploit code.

## Other vulnerabilities in SemanticMediaWiki

- [CVE-2022-48614](https://insights.sbomify.com/CVE-2022-48614/): Cross-site Scripting in Semantic MediaWiki (medium 6.1)
- [CVE-2026-116874](https://insights.sbomify.com/CVE-2026-116874/): SemanticMediaWiki 3.1.0 before 7.3.1 Reflected XSS via JsonResultPrinter Default Parameter (medium 5.3)
- [CVE-2026-116875](https://insights.sbomify.com/CVE-2026-116875/): SemanticMediaWiki 3.0.0 before 7.3.1 Reflected XSS via Special:Ask Separator Parameters (medium 5.3)
- [CVE-2026-116884](https://insights.sbomify.com/CVE-2026-116884/): SemanticMediaWiki 5.0.0 before 7.3.1 Stored XSS via Tooltip Module data-* Attributes (medium 5.3)
- [CVE-2026-116889](https://insights.sbomify.com/CVE-2026-116889/): SemanticMediaWiki 2.5.0 before 7.3.1 Stored XSS via Special:Browse Code Property (medium 5.3)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-116891 and fix it if it is affected.

What it is: CVE-2026-116891 is a medium-severity vulnerability in SemanticMediaWiki, published on 27 Oct 2026. 
Exploitation: There is no known exploitation of CVE-2026-116891 in the wild and no public exploit code.

Affected packages and fixed versions:
- mediawiki/semantic-media-wiki (Packagist): affected from 4.2.0; fixed in 7.2.1
- mediawiki/semantic-media-wiki (Packagist): affected from 4.2.0; fixed in 7.2.1

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-116891/ (Markdown: https://insights.sbomify.com/CVE-2026-116891/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-116891
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-116891
- OSV: https://osv.dev/vulnerability/CVE-2026-116891

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-116891/
Summaries are generated and may contain mistakes; the official description above is the record.