Stored XSS via raw system-message HTML rendering
Published Jul 1, 2026 · Updated Jul 1, 2026
Stored XSS in MediaWiki 1.46.0-rc.0 allows remote authenticated users to execute script in visitors' browsers via a system message. SpecialBlock.vue passes the parsed additional-blocks system message to Vue's v-html directive, which inserts the resulting markup into the DOM without MediaWiki's i18n HTML handling. Exploitation requires permission to edit system messages and a visitor to open the Codex version of Special:Block; script runs in that visitor's browser context.
Summary
What happened
Stored XSS in MediaWiki 1.46.0-rc.0 allows remote authenticated users to execute script in visitors' browsers via a system message. SpecialBlock.vue passes the parsed additional-blocks system message to Vue's v-html directive, which inserts the resulting markup into the DOM without MediaWiki's i18n HTML handling. Exploitation requires permission to edit system messages and a visitor to open the Codex version of Special:Block; script runs in that visitor's browser context.
The record
- CVE
- CVE-2026-58035
- Published
- Jul 1, 2026
- Updated
- Jul 1, 2026
- Vendor
- Wikimedia Foundation
- Product
- MediaWiki
- Classifications
- CWE-79, T1059.007
- Attack vector
- network
- Privileges
- authenticated
Timeline
How it unfolded
- Jul 1, 2026CVE publishedPublication date reported by the CVE source.
- Jul 1, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=1.46.0-rc.0 <1.46.0
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
No public exploit references are available in this record.
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Technologies
Your stack
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Your stack
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