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CVE-2024-27443

Medium CVSS 6.1 Known exploited

Published 2024-08-12 · last changed 2026-06-17 · added to CISA KEV 2025-05-19

This one is being exploited in the wild.

CISA added CVE-2024-27443 to the Known Exploited Vulnerabilities catalog on 2025-05-19. Federal agencies are required to remediate it on a deadline. If you have affected machines, this is the class of finding that moves ahead of the rest of the queue.

The fix

We hold no Microsoft remediation data for CVE-2024-27443, which normally means it is not a Windows CVE. For non-Microsoft software the fix is the vendor's own updated release, and the affected versions are listed below.

What it is

An issue was discovered in Zimbra Collaboration (ZCS) 9.0 and 10.0. A Cross-Site Scripting (XSS) vulnerability exists in the CalendarInvite feature of the Zimbra webmail classic user interface, because of improper input validation in the handling of the calendar header. An attacker can exploit this via an email message containing a crafted calendar header with an embedded XSS payload. When a victim views this message in the Zimbra webmail classic interface, the payload is executed in the context of the victim's session, potentially leading to execution of arbitrary JavaScript code.

Sources

CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N