CISA confirmed this vulnerability is used in real attacks on 20.04.2026. Remediation deadline for US federal agencies: 23.04.2026.
Required action: Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable. https://wiki.zimbra.com/wiki/Zimbra_Security_Advisories ; https://nvd.nist.gov/vuln/detail/CVE-2025-48700
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.
Data: CVE.org, NVD, CISA KEV, FIRST EPSS, Ubuntu. Published as the sources state it, in English.
| Vendor | Product | Versions | |
|---|---|---|---|
| synacor | zimbra collaboration suite | 10.0.0 – < 10.0.12 |
cpe:2.3:a:synacor:zimbra_collaboration_suite:*:*:*:*:*:*:*:* ≥ 10.0.0 < 10.0.12cpe:2.3:a:synacor:zimbra_collaboration_suite:*:*:*:*:*:*:*:* ≥ 10.1.0 < 10.1.4cpe:2.3:a:synacor:zimbra_collaboration_suite:8.8.15:-:*:*:*:*:*:*cpe:2.3:a:synacor:zimbra_collaboration_suite:8.8.15:p1:*:*:*:*:*:*cpe:2.3:a:synacor:zimbra_collaboration_suite:8.8.15:p10:*:*:*:*:*:*cpe:2.3:a:synacor:zimbra_collaboration_suite:8.8.15:p11:*:*:*:*:*:*cpe:2.3:a:synacor:zimbra_collaboration_suite:8.8.15:p12:*:*:*:*:*:*cpe:2.3:a:synacor:zimbra_collaboration_suite:8.8.15:p13:*:*:*:*:*:*cpe:2.3:a:synacor:zimbra_collaboration_suite:8.8.15:p14:*:*:*:*:*:*cpe:2.3:a:synacor:zimbra_collaboration_suite:8.8.15:p15:*:*:*:*:*:*cpe:2.3:a:synacor:zimbra_collaboration_suite:8.8.15:p16:*:*:*:*:*:*cpe:2.3:a:synacor:zimbra_collaboration_suite:8.8.15:p17:*:*:*:*:*:*cpe:2.3:a:synacor:zimbra_collaboration_suite:8.8.15:p18:*:*:*:*:*:*cpe:2.3:a:synacor:zimbra_collaboration_suite:8.8.15:p19:*:*:*:*:*:*cpe:2.3:a:synacor:zimbra_collaboration_suite:8.8.15:p2:*:*:*:*:*:*cpe:2.3:a:synacor:zimbra_collaboration_suite:8.8.15:p20:*:*:*:*:*:*cpe:2.3:a:synacor:zimbra_collaboration_suite:8.8.15:p21:*:*:*:*:*:*cpe:2.3:a:synacor:zimbra_collaboration_suite:8.8.15:p22:*:*:*:*:*:*cpe:2.3:a:synacor:zimbra_collaboration_suite:8.8.15:p23:*:*:*:*:*:*cpe:2.3:a:synacor:zimbra_collaboration_suite:8.8.15:p24:*:*:*:*:*:*cpe:2.3:a:synacor:zimbra_collaboration_suite:8.8.15:p25:*:*:*:*:*:*cpe:2.3:a:synacor:zimbra_collaboration_suite:8.8.15:p26:*:*:*:*:*:*cpe:2.3:a:synacor:zimbra_collaboration_suite:8.8.15:p27:*:*:*:*:*:*cpe:2.3:a:synacor:zimbra_collaboration_suite:8.8.15:p28:*:*:*:*:*:*cpe:2.3:a:synacor:zimbra_collaboration_suite:8.8.15:p29:*:*:*:*:*:*cpe:2.3:a:synacor:zimbra_collaboration_suite:8.8.15:p3:*:*:*:*:*:*cpe:2.3:a:synacor:zimbra_collaboration_suite:8.8.15:p30:*:*:*:*:*:*cpe:2.3:a:synacor:zimbra_collaboration_suite:8.8.15:p31:*:*:*:*:*:*cpe:2.3:a:synacor:zimbra_collaboration_suite:8.8.15:p31.1:*:*:*:*:*:*cpe:2.3:a:synacor:zimbra_collaboration_suite:8.8.15:p32:*:*:*:*:*:*cpe:2.3:a:synacor:zimbra_collaboration_suite:8.8.15:p33:*:*:*:*:*:*cpe:2.3:a:synacor:zimbra_collaboration_suite:8.8.15:p34:*:*:*:*:*:*cpe:2.3:a:synacor:zimbra_collaboration_suite:8.8.15:p35:*:*:*:*:*:*cpe:2.3:a:synacor:zimbra_collaboration_suite:8.8.15:p36:*:*:*:*:*:*cpe:2.3:a:synacor:zimbra_collaboration_suite:8.8.15:p37:*:*:*:*:*:*cpe:2.3:a:synacor:zimbra_collaboration_suite:8.8.15:p38:*:*:*:*:*:*cpe:2.3:a:synacor:zimbra_collaboration_suite:8.8.15:p39:*:*:*:*:*:*cpe:2.3:a:synacor:zimbra_collaboration_suite:8.8.15:p4:*:*:*:*:*:*cpe:2.3:a:synacor:zimbra_collaboration_suite:8.8.15:p40:*:*:*:*:*:*cpe:2.3:a:synacor:zimbra_collaboration_suite:8.8.15:p41:*:*:*:*:*:*cpe:2.3:a:synacor:zimbra_collaboration_suite:8.8.15:p42:*:*:*:*:*:*cpe:2.3:a:synacor:zimbra_collaboration_suite:8.8.15:p43:*:*:*:*:*:*cpe:2.3:a:synacor:zimbra_collaboration_suite:8.8.15:p44:*:*:*:*:*:*cpe:2.3:a:synacor:zimbra_collaboration_suite:8.8.15:p45:*:*:*:*:*:*cpe:2.3:a:synacor:zimbra_collaboration_suite:8.8.15:p46:*:*:*:*:*:*cpe:2.3:a:synacor:zimbra_collaboration_suite:8.8.15:p5:*:*:*:*:*:*cpe:2.3:a:synacor:zimbra_collaboration_suite:8.8.15:p6:*:*:*:*:*:*cpe:2.3:a:synacor:zimbra_collaboration_suite:8.8.15:p7:*:*:*:*:*:*cpe:2.3:a:synacor:zimbra_collaboration_suite:8.8.15:p8:*:*:*:*:*:*cpe:2.3:a:synacor:zimbra_collaboration_suite:8.8.15:p9:*:*:*:*:*:*cpe:2.3:a:synacor:zimbra_collaboration_suite:9.0.0:-:*:*:*:*:*:*cpe:2.3:a:synacor:zimbra_collaboration_suite:9.0.0:p1:*:*:*:*:*:*cpe:2.3:a:synacor:zimbra_collaboration_suite:9.0.0:p10:*:*:*:*:*:*cpe:2.3:a:synacor:zimbra_collaboration_suite:9.0.0:p11:*:*:*:*:*:*cpe:2.3:a:synacor:zimbra_collaboration_suite:9.0.0:p12:*:*:*:*:*:*cpe:2.3:a:synacor:zimbra_collaboration_suite:9.0.0:p13:*:*:*:*:*:*cpe:2.3:a:synacor:zimbra_collaboration_suite:9.0.0:p14:*:*:*:*:*:*cpe:2.3:a:synacor:zimbra_collaboration_suite:9.0.0:p15:*:*:*:*:*:*cpe:2.3:a:synacor:zimbra_collaboration_suite:9.0.0:p16:*:*:*:*:*:*cpe:2.3:a:synacor:zimbra_collaboration_suite:9.0.0:p17:*:*:*:*:*:*Our free, open-source honeypot sensor waits on ports your server does not use and reports the scanners and attackers that connect to a shared blocklist.