# CVE-2026-77607: Semantic MediaWiki reflected XSS in Special:Ask separator parameter

Source: https://junglewise.ai/threats/cve-2026-77607-semantic-mediawiki-reflected-xss-in-special-ask-separator  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-09-18. Updated: 2026-09-25  
License: CC BY 4.0 with a link back

CVE-2026-77607 · Severity: medium · CVSS 6.1 · Published 2026-09-18

Semantic MediaWiki is a semantic search extension for MediaWiki that allows structured querying of wiki content. A reflected cross-site scripting (XSS) vulnerability in the `sep` parameter of the Special:Ask page allows unauthenticated attackers to inject arbitrary HTML and JavaScript into the page, potentially stealing user session cookies, defacing content, or performing actions on behalf of authenticated users.

Technologies: [mediawiki/semantic-media-wiki (Packagist)](https://junglewise.ai/threats/technologies/mediawiki-semantic-media-wiki), [Semantic MediaWiki](https://junglewise.ai/threats/technologies/semantic-mediawiki). Vendors: [Packagist](https://junglewise.ai/threats/vendors/packagist), [Semantic MediaWiki](https://junglewise.ai/threats/vendors/semantic-mediawiki).

## Quick answers

**Is CVE-2026-77607 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-77607 being exploited in the wild.

**How severe is CVE-2026-77607?** Medium severity, with a CVSS score of 6.1, published 18 September 2026.

**Which products and versions are affected?** mediawiki/semantic-media-wiki (Packagist) <= 7.1.0, ECOSYSTEM:introduced=0,fixed=7.2.0; Semantic MediaWiki <= 7.1.0.

**Is there a fix for CVE-2026-77607?** Yes. mediawiki/semantic-media-wiki (Packagist): upgrade to 7.2.0 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-77607 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-77607?** Check whether you run mediawiki/semantic-media-wiki (Packagist) or Semantic MediaWiki at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- mediawiki/semantic-media-wiki (Packagist): upgrade to 7.2.0 or later

  ```sh
  composer require mediawiki/semantic-media-wiki:^7.2.0
  ```


## Technical details

The vulnerability is a reflected XSS flaw (CWE-79) in the Special:Ask query interface where the table separator (`sep`) parameter is inserted verbatim into generated HTML without sanitization. An attacker can craft a URL with malicious HTML/JavaScript in the `sep` parameter; when a user visits this link, the payload executes in their browser. The vulnerability is reachable without authentication for both normal HTML output and raw request mode (`request_type=raw`). The fix (version 7.2.0) escapes the `sep` parameter in all non-wiki output modes while preserving safe variants like `<br>` tags for legitimate line-break separators.

## Affected products

- Semantic MediaWiki Semantic MediaWiki <= 7.1.0

## Identifiers

- CVE-2026-77607
- GHSA-7xv3-gf2g-498h

## Timeline

- 2026-07-18: disclosed
- 2026-07-18: patched: Version 7.2.0 released
- 2026-09-18: advisory

## References

- [https://api.github.com/users/krabina](https://api.github.com/users/krabina)

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