# CVE-2026-77616: Semantic MediaWiki affected by reflected XSS in `Special:Ask` via a forged cursor pagination token

> Reflected XSS in Semantic MediaWiki allows attackers to execute arbitrary scripts in victims' browsers via a crafted cursor token in Special:Ask.

- **Severity:** Medium 6.1 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** Yes
- **Published:** 18 Sep 2026
- **Updated:** 18 Sep 2026
- **Also known as:** GHSA-cx86-7xwp-w9wf

## What is CVE-2026-77616?

CVE-2026-77616 is a medium-severity cross-site scripting vulnerability in SemanticMediaWiki, published on 18 Sep 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

### Official description

Semantic MediaWiki is a free, open-source extension to MediaWiki that lets users store and query data within the wiki's pages. In versions 7.0.0 through 7.1.0, `Special:Ask` accepts a `cursor` query parameter for keyset pagination (added in 7.0.0). The token is decoded by `CursorEncoder`, which is an **unsigned** base64url-encoded JSON blob, so its contents are fully attacker-controlled. When the cursor's sort anchor does not match the request's `sort=` / `order=`, `QueryCreator::applyCursorIfRequested()` builds an error message by interpolating the attacker-controlled `sort_prop` / `sort_order` values into a raw string via `Query::addErrors()`. Unlike SMW's message-key errors, this raw string bypasses the message layer's sanitization (`ProcessingErrorMsgHandler::normalizeAndDecodeMessages()` passes a non-key, non-encoded string through unchanged). `ErrorWidget::queryError()` then assembles the errors and passes them to `Html::errorBox()`, whose first argument is emitted as raw HTML. The result is a reflected cross-site scripting vulnerability: a crafted `cursor` token containing markup in `sort_prop` (or `sort_order`) executes script in the victim's browser on the wiki origin. No authentication or special permission is required. The payload is delivered via a crafted link. Version 7.2.0 contains a fix.

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

## Which versions are affected by CVE-2026-77616?

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


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `mediawiki/semantic-media-wiki` | Packagist | From 7.0.0 | 7.2.0 |
| `mediawiki/semantic-media-wiki` | Packagist | From 7.0.0 | 7.2.0 |

## How do I fix CVE-2026-77616?

Upgrade mediawiki/semantic-media-wiki to 7.2.0 or later.

## Is CVE-2026-77616 being exploited?

There is no known exploitation of CVE-2026-77616 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-77616 and fix it if it is affected.

What it is: CVE-2026-77616 is a medium-severity cross-site scripting vulnerability in SemanticMediaWiki, published on 18 Sep 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2026-77616 in the wild and no public exploit code.

Affected packages and fixed versions:
- mediawiki/semantic-media-wiki (Packagist): affected from 7.0.0; fixed in 7.2.0
- mediawiki/semantic-media-wiki (Packagist): affected from 7.0.0; fixed in 7.2.0

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-2026-77616/ (Markdown: https://insights.sbomify.com/CVE-2026-77616/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-77616
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-77616
- OSV: https://osv.dev/vulnerability/CVE-2026-77616

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From sbomify Insights: https://insights.sbomify.com/CVE-2026-77616/
Summaries are generated and may contain mistakes; the official description above is the record.