CVE-2025-27915
CVSS v3
5.4
MEDIUM
EPSS Score
27.7 %
exploit probability
CISA KEV
Yes
known exploited
Exploitation
—
SSVC status
Description
An issue was discovered in Zimbra Collaboration (ZCS) 9.0 and 10.0 and 10.1. A stored cross-site scripting (XSS) vulnerability exists in the Classic Web Client due to insufficient sanitization of HTML content in ICS files. When a user views an e-mail message containing a malicious ICS entry, its embedded JavaScript executes via an ontoggle event inside a <details> tag. This allows an attacker to run arbitrary JavaScript within the victim's session, potentially leading to unauthorized actions such as setting e-mail filters to redirect messages to an attacker-controlled address. As a result, an attacker can perform unauthorized actions on the victim's account, including e-mail redirection and data exfiltration.
CISA Known Exploited Vulnerability
- Date Added
- 2025-10-07
- Patch Due Date
- 2025-10-28
- Ransomware Use
- Unknown
Technical details
- Published
- 2025-03-12
Frequently asked questions
What is CVE-2025-27915?
An issue was discovered in Zimbra Collaboration (ZCS) 9.0 and 10.0 and 10.1. A stored cross-site scripting (XSS) vulnerability exists in the Classic Web Client due to insufficient sanitization of HTML content in ICS files. When a user views an e-mail message containing a malicious ICS entry, its embedded JavaScript executes via an ontoggle event inside a <details> tag. This allows an attacker to run arbitrary JavaScript within the victim's session, potentially leading to unauthorized actions such as setting e-mail filters to redirect messages to an attacker-controlled address. As a result, an attacker can perform unauthorized actions on the victim's account, including e-mail redirection and data exfiltration.
Is CVE-2025-27915 actively exploited?
Yes. CVE-2025-27915 is on the CISA Known Exploited Vulnerabilities (KEV) catalog, meaning it has been confirmed as actively exploited in the wild. CISA requires federal agencies to patch by 2025-10-28.
What is the CVSS score for CVE-2025-27915?
CVE-2025-27915 has a CVSS v3 base score of 5.4 (MEDIUM severity).
Is CVE-2025-27915 affecting your environment?
Use isMalicious to check if any of your IPs or domains are associated with this vulnerability's IOCs.
No credit card required · 500 free checks/month · Free API key
Other 2025 vulnerabilities worth triaging
Ranked by exploit probability (EPSS).