CVE-2026-52854
Stored XSS in MediaWiki Maps extension allows script execution in viewers' browsers.
Is CVE-2026-52854 being exploited?
Not confirmed. CVE-2026-52854 does not appear in CISA's Known Exploited Vulnerabilities catalog, which records only exploitation that has been observed and reported publicly. That is evidence of absence of a report, not evidence the flaw is unattacked. EPSS currently estimates a 0.64% probability of exploitation in the next 30 days.
How severe is CVE-2026-52854?
CVE-2026-52854 is rated High with a CVSS score of 8.6. Severity describes how bad exploitation would be, not how likely it is: pair it with exploitation evidence before deciding what to patch first.
Is there a patch for CVE-2026-52854?
Yes. A fix has been recorded for CVE-2026-52854. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-52854 affect?
CVE-2026-52854 affects MediaWiki Maps extension <12.1.3, Leaflet service display_map, jquery.leaflet.js, MediaWiki sites using Maps. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-52854?
Upgrade Maps extension to 12.1.3 or sanitize overlay names
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Stored cross-site scripting via overlays in display_map; attacker with edit rights can run scripts in viewers' sessions, steal tokens, perform actions as the victim.
Patch when possible
- affected< 12.1.3
As published in the CVE Program record. A version outside these ranges is not a statement that it is unaffected — vendors sometimes understate a range, and distribution-backported builds carry upstream numbers that do not reflect what was patched into them.