What is CVE-2026-58034?

CVE-2026-58034 is a medium-severity vulnerability in MediaWiki, classified under Cross-site Scripting. CVSS score: 4.8/10. Published 2026-07-01.

How severe is CVE-2026-58034?

Medium severity. CVSS v3 base score is 4.8 out of 10.

XSS in MediaWiki

CVE-2026-58034

Improper Neutralization of Input During Web Page Generation (XSS or 'Cross-site Scripting') vulnerability in Wikimedia Foundation CheckUser. This vulnerability is associated with program files modules/ext.CheckUser.TempAccounts/components/blockConnectedTempAccountsField.Vue. This issue affects CheckUser: from 1.46.0-rc.0 before 1.46.0.

Vulnerability class: XSS (Cross-Site Scripting)

EPSS: 0.002 (6.6th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 4.8 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:N.

Affected products

Mediawiki — versions 1.46.0
Wikimedia Foundation Checkuser — versions 1.46.0-rc.0

Weakness classification (CWE)

CWE-79 — Cross-site Scripting

References

c4f26cc8-17ff-4c99-b5e2-38fc1793eacc (Permissions Required)

Frequently asked questions

What is CVE-2026-58034?: CVE-2026-58034 is a medium-severity vulnerability in MediaWiki, classified under Cross-site Scripting. CVSS score: 4.8/10. Published 2026-07-01.
How severe is CVE-2026-58034?: Medium severity. CVSS v3 base score is 4.8 out of 10.