Medium severity · published Jun 23, 2025
CVE-2025-48700
Synacor Zimbra Collaboration Suite (ZCS) Cross-site Scripting Vulnerability
In wildKEV
6.1
CVSS
1.7%
EPSS
Yes
On KEV
Description
An issue was discovered in Zimbra Collaboration (ZCS) 8.8.15 and 9.0 and 10.0 and 10.1. A Cross-Site Scripting (XSS) vulnerability in the Zimbra Classic UI allows attackers to execute arbitrary JavaScript within the user's session, potentially leading to unauthorized access to sensitive information. This issue arises from insufficient sanitization of HTML content, specifically involving crafted tag structures and attribute values that include an @import directive and other script injection vectors. The vulnerability is triggered when a user views a crafted e-mail message in the Classic UI, requiring no additional user interaction.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
Required
Confidentiality
Low
Integrity
Low
Availability
None
Scope
Changed
Exploitation
Is it being used?
Exploit prediction (EPSS)1.7% · higher than 77% of CVEs
Exploited in the wildYes
CISA KEVListed Apr 20, 2026
Federal remediation dueApr 23, 2026
Ransomware campaign useNot known
Affected products
Which versions
ZC
Zimbra Collaboration Suite · Synacor
10.0.0 before 10.0.12; 10.1.0 before 10.1.4; 8.8.15; 8.8.15; 8.8.15; 8.8.15; +34 more · source: NVD
ZC
Zimbra Collaboration Suite (ZCS) · Synacor
All versions, or not specified · source: KEV
In the news
AdvisoryHigh
CISA Adds Eight Known Exploited Vulnerabilities to Catalog
CISA has added eight new vulnerabilities to its Known Exploited Vulnerabilities (KEV) Catalog , based on evidence of active exploitation.
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CVE-2025-2749 Kentico Xperience Path Traversal Vulnerability
CVE-2025-32975 Quest KACE Systems Management Appliance (SMA) Improper Authentication Vulnerability
CVE-2025-48700 Synacor Zimbra Collaboration Suite (ZCS) Cross-site Scripting Vulnerability
CVE-2026-20122 Cisco Catalyst SD-WAN Manager Incorrect Use of Privileged APIs Vulnerability
CVE-2026-20128 Cisco Catalyst SD-WAN Manager Storing Passwords in a Recoverable Format Vulnerability
CVE-2026-20133 Cisco Catalyst SD-WAN Manager Exposure of Sensitive Information to an Unauthorized Actor Vulnerability
These types of vulnerabilities are frequent attack vectors for malicious cyber actors and pose significant risks to the federal enterprise.
Binding Operational Directive (BOD) 22-01: Reducing the Significant Risk of Known Exploited Vulnerabilities established the KEV Catalog as a living list of known Common Vulnerabilities and Exposures (CVEs) that carry significant risk to the federal enterprise. BOD 22-01 requires Federal Civilian Executive Branch (FCEB) agencies to remediate identified vulnerabilities by the due date to protect FCEB networks against active threats. Se...
Apr 20, 2026·CISA Advisories
VulnerabilityHigh
[CISA KEV] CVE-2025-48700: Synacor Zimbra Collaboration Suite (ZCS) - Synacor Zimbra Collaboration Suite (ZCS) Cross-site Scripting Vulnerability
Synacor Zimbra Collaboration Suite (ZCS) contains a cross-site scripting vulnerability that could allow attackers to execute arbitrary JavaScript within the user's session, potentially leading to unauthorized access to sensitive information.
ZCZimbra Collaboration Suite (ZCS)CVE-2025-48700
Apr 20, 2026·CISA KEV
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2025-48700
CVE.org
https://www.cve.org/CVERecord?id=CVE-2025-48700
CISA KEV catalogue
https://www.cisa.gov/known-exploited-vulnerabilities-catalog
wiki.zimbra.com
https://wiki.zimbra.com/wiki/Zimbra_Security_Advisories
wiki.zimbra.com
https://wiki.zimbra.com/wiki/Security_Center
wiki.zimbra.com
https://wiki.zimbra.com/wiki/Zimbra_Responsible_Disclosure_Policy
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