CVE-2026-34091
📛 CVE Title
User localization leaked by AbuseFilter + EventStream
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.
Overview
- State
- PUBLISHED
- Assigner (CNA)
- wikimedia-foundation
- CVSS severity
- MEDIUM
- CVSS score
- 5.5 / 10
- CVSS vector
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:P/R:U- Effective score
- 5.5 / 10 MEDIUM source: CNA overview
- CWE(s)
-
CWE-200 - Reserved
- 2026-03-25
- Published
- 2026-05-11 16:55 UTC
- Last updated
- 2026-05-11 18:03 UTC
- Source
- https://raw.githubusercontent.com/CVEProject/cvelistV5/main/cves/2026/34xxx/CVE-2026-34091.json
- Linked Threat
- CVE-2026-34091 — CVE-2026-34091
NVD triage scoring NVD CVE 2.0
Layer NVD adds on top of the CNA's CVE record — published / last-modified timestamps, exploitability / impact subscores, and the FIRST.org EPSS probability that this CVE will be exploited in the wild in the next 30 days.
- NVD published
- 2026-05-11 16:17:30 UTC
- NVD last modified
- 2026-05-14 16:42:10 UTC
- NVD CVSS v3.1
- 7.5 / 10 HIGH source: nvd@nist.gov
- NVD CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N- Exploitability subscore
- 3.9 / 10
- Impact subscore
- 3.6 / 10
- EPSS score
- 0.0004 (probability of exploitation in next 30 days)
- EPSS percentile
- 12.15% vs all CVEs — higher = more likely to be exploited, as of 2026-05-24
NVD / KEV / EPSS data refreshed 2026-05-25 12:38 UTC. Re-run the 🛰 Backfill from NVD button above to refresh.
European Union Vulnerability Database ENISA EUVD
ENISA's official EU repository for curated vulnerability intelligence. Carries a separate identifier (EUVD-YYYY-NNNN) and frequently exposes an earlier-published description + CVSS than NVD does.
- EUVD ID
-
EUVD-2026-29063 - Assigner
- wikimedia-foundation
- Published
- May 11, 2026, 2:55:33 PM
- Updated
- May 11, 2026, 4:03:07 PM
- EUVD base score (CVSS 4.0)
-
5.5 / 10
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:P/R:U - EUVD-reported EPSS
- 0.0400
- Vendors
- Wikimedia Foundation
- Products
-
mediawiki (* <1.43.7, 1.44.4, 1.45.2)mediawiki (* <1.43.7, 1.44.4, 1.45.2)
ENISA 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.
EUVD references (1)
Affected products (1)
| Vendor | Product | Versions | Platforms |
|---|---|---|---|
| Wikimedia Foundation | MediaWiki |
* (affected)
|
— |
Affected products — CPE 2.3 (1) NVD
NVD's normalized CPE 2.3 matchers, used by vendor tools (vulnerability scanners, asset managers) for automated detection. Compare with the CNA's free-text "Affected products" section above.
cpe:2.3:a:mediawiki:mediawiki:*:*:*:*:*:*:*:*
Vendor references (1)
References embedded in the original CVE record by the assigning CNA.
MITRE references (1) cveawg.mitre.org
Pulled from MITRE's CVE Services API by the 🛰 Backfill from MITRE button.
Web references (6)
DuckDuckGo results ranked by threat-intel / vendor advisory domains. Generated by the 🔎 Find references (web) button above — same flow as the Remediations search.
- http://cwe.mitre.org/data/definitions/200.html rapid7:cwe.mitre.org
- https://attackerkb.com/topics/CVE-2026-34091 rapid7:attackerkb.com
- https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-29063 rapid7:euvd.enisa.europa.eu
- https://nvd.nist.gov/vuln/detail/CVE-2026-34091 tenable:nvd.nist.gov
- https://www.first.org/epss/ tenable:www.first.org
- https://www.cve.org/CVERecord?id=CVE-2026-34091 tenable:www.cve.org
NVD-tagged references (1)
Reference list NVD curates from the CNA record, vendor advisories, and third-party reports. The tag chips below are NVD's analyst-assigned categories.
- https://phabricator.wikimedia.org/T411305 c4f26cc8-17ff-4c99-b5e2-38fc1793eacc Issue TrackingVendor Advisory
Remediations (15)
Remediations are stored against the linked Threat row; the list below is deduplicated across both pages.
-
web:cyberpress.org
The U.S. Cybersecurity and Infrastructure Security Agency (CISA) has added two actively exploited Microsoft Defender vulnerabilities to its Known Exploited Vulnerabilities (KEV) catalog, issuing an urgent remediation directive for federal agencies with a due date of June 3, 2026 .
2026-05-23 21:01 UTC -
web:cyberscoop.com
Threats Microsoft addresses 137 vulnerabilities in May's Patch Tuesday, including 13 rated critical The high volume of vulnerabilities reflects a growing trend researchers have been anticipating as artificial intelligence models are deployed to find previously uncovered defects in code.
2026-05-23 21:01 UTC -
web:krebsonsecurity.com
Microsoft expects that exploitation is more likely. May's Patch Tuesday is a welcome respite from April, which saw Microsoft fix a near-record 167 security flaws.
2026-05-23 21:01 UTC -
web:msrc.microsoft.com
Security Update Guide - Microsoft Security Response Center
2026-05-23 21:01 UTC -
web:portal.msrc.microsoft.com
The Security Update Guide provides information on the latest Microsoft security updates, helping users understand and address potential vulnerabilities effectively.
2026-05-23 21:01 UTC -
web:support.servicenow.com
Overview The advisories below document publicly disclosed Common Vulnerabilities and Exposures ( CVEs ) in the Now Platform by ServiceNow. Because ServiceNow uses various methods to communicate vulnerability information, patches, and other fixes, customers should review family, security patch , and hotfix release notes, which are available at https://docs.servicenow.com, for a complete list of ...
2026-05-23 21:01 UTC -
web:www.bleepingcomputer.com
Today is Microsoft's April 2026 Patch Tuesday with security updates for 167 flaws, including 2 zero-day vulnerabilities.
2026-05-23 21:01 UTC -
web:www.crowdstrike.com
Microsoft's April 2026 Patch Tuesday addresses 164 CVEs , featuring 8 Critical vulnerabilities, one exploited zero-day, and one disclosed zero-day.
2026-05-23 21:01 UTC -
web:www.microsoft.com
Security Update Guide Notifications Microsoft's free Security Update Guide Notifications provide links to security-related software updates and notification of re-released security updates. These notifications are sent via email throughout the month as needed.
2026-05-23 21:01 UTC -
web:www.oracle.com
This Critical Patch Update contains 481 new security patches across the product families listed below. Please note that an MOS note summarizing the content of this Critical Patch Update and other Oracle Software Security Assurance activities is located at April 2026 Critical Patch Update: Executive Summary and Analysis.
2026-05-23 21:01 UTC -
web:msrc.microsoft.com
The Microsoft Security Response Center (MSRC) investigates all reports of security vulnerabilities affecting Microsoft products and services, and provides the information here as part of the ongoing effort to help you manage security risks and help keep your systems protected.
2026-05-26 02:52 UTC -
web:www.bleepingcomputer.com
Today is Microsoft's March 2026 Patch Tuesday with security updates for 79 flaws, including 2 publicly disclosed zero-day vulnerabilities.
2026-05-26 02:52 UTC -
web:www.forbes.com
Updated May 17: This article, originally published May 16, has been updated to include further details on the emergency mitigation process recommended after the CVE - 2026 -42897 Microsoft Exchange ...
2026-05-26 02:52 UTC -
web:www.pcworld.com
This month's Patch Tuesday includes an actively exploited Office zero-day vulnerability and several critical RCE bugs in Windows and Remote Desktop.
2026-05-26 02:52 UTC -
web:zecurit.com
Get the complete breakdown of Microsoft's May 2026 Patch Tuesday. We analyze the latest security updates and all critical CVEs .
2026-05-26 02:52 UTC
AI Forensic Analysis
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Raw JSON
The full cvelistV5 record. Download as CVE-2026-34091.json.
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