# CVE-2026-34091: mediawiki: Exposure of Sensitive Information to an Unauthorized Actor vulnerability in Wikimedia Foundation MediaWiki

CVE-2026-34091 is fixed in 2 products on 1 platform, first by mediawiki 1:1.43.8+dfsg-2, released May 11, 2026. It is not reported as exploited. Patch Radar priority: High.

- Web page: https://patchblox.com/security/cve/CVE-2026-34091
- Priority: High
- CVSS: 7.5 (high)
- EPSS: 0.0029
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: May 11, 2026

## Description

Exposure of Sensitive Information to an Unauthorized Actor vulnerability in Wikimedia Foundation MediaWiki.  This issue affects MediaWiki: from * before 1.43.7, 1.44.4, 1.45.2.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | mediawiki Debian 13.5 (trixie) | 1:1.43.8+dfsg-1~deb13u1 | [DEBIAN-CVE-2026-34091](https://patchblox.com/security/data/fix/linux/debian-cve-2026-34091.md) | May 15, 2026 |
| Linux | mediawiki Debian 14 | 1:1.43.8+dfsg-1 | [DEBIAN-CVE-2026-34091](https://patchblox.com/security/data/fix/linux/debian-cve-2026-34091.md) | May 15, 2026 |
| Linux | mediawiki Ubuntu 26.04.1 LTS (resolute) | 1:1.43.8+dfsg-2 | [mediawiki 1:1.43.8+dfsg-2](https://patchblox.com/security/data/fix/linux/ubuntu-resolute-mediawiki-1-1.43.8-dfsg-2.md) | May 11, 2026 |
| Linux | mediawiki-classes Ubuntu 26.04.1 LTS (resolute) | 1:1.43.8+dfsg-2 | [mediawiki-classes 1:1.43.8+dfsg-2](https://patchblox.com/security/data/fix/linux/ubuntu-resolute-mediawiki-classes-1-1.43.8-dfsg-2.md) | May 11, 2026 |

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Data as of 2026-11-08T06:59:42Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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