CVE-2025-48700
MediumExploitedPublic exploitA 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.
Published Jun 23, 2025 · Updated Sep 14, 2026
Key Facts
Patch immediately- CVE-2025-48700 is a medium-severity vulnerability (CVSS 6.1 v3.1) affecting Zimbra Collaboration Suite (Synacor).
- It is exploited in the wild, listed in CISA KEV, Industry KEV feed, CIRCL KEV, ENISA EUVD since Apr 20, 2026. Public exploit code is available.
- EPSS estimates a 1.7% probability of exploitation in the next 30 days.
- Fixed versions are available, including Zimbra Collaboration Suite 10.0.12.
- Brandefense priority: patch immediately, because it is listed as exploited in the wild.
CVSS v3.1
6.1
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
EPSS (30-day exploit likelihood)
1.7%
Higher than 76.9% of all scored CVEs
Exploited in the wild
Yes
4 catalog listings
Public exploit code
Available
Proof-of-concept or weaponized module
Get the full CVE-2025-48700 brief as a PDF
Every affected product and fixed release, exploitation status and a first 24 hours response checklist, emailed within minutes.
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.
Known-Exploited Catalog Listings
| Catalog | Added | Remediation due | Ransomware use |
|---|---|---|---|
| CISA KEV | Apr 20, 2026 | Apr 23, 2026 | Not reported |
| Industry KEV feed | Apr 20, 2026 | Apr 23, 2026 | Not reported |
| CIRCL KEV | Apr 20, 2026 | Apr 23, 2026 | Not reported |
| ENISA EUVD | Apr 20, 2026 | n/a | Not reported |
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.
Affected Products
93 affected entries in total| Product | Affected versions | Fixed in |
|---|---|---|
| Zimbra Collaboration SuiteSynacor | 8.8.15, 8.8.15-p1, 8.8.15-p10, 8.8.15-p11, 8.8.15-p12, 8.8.15-p13, 8.8.15-p14, 8.8.15-p15 | 10.0.12 |
Patched Releases
Zimbra Collaboration Suite
10.0.12
Timeline
Publicly disclosed
Jun 23, 2025
Added to CISA KEV
Apr 20, 2026
Added to Industry KEV feed
Apr 20, 2026
Added to CIRCL KEV
Apr 20, 2026
Added to ENISA EUVD
Apr 20, 2026
Last updated
Sep 14, 2026
Weakness Type
- CWE-79 Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
References
- advisoryhttps://github.com/CVEProject/cvelistV5/tree/main/cves/2025/48xxx/CVE-2025-48700.json
- advisoryhttps://nvd.nist.gov/vuln/detail/CVE-2025-48700
- advisoryhttps://wiki.zimbra.com/wiki/Zimbra_Security_Advisories
- exploitVulnCheck exploitation report
- exploitVulnCheck exploitation report
FAQ
Common Questions.
An issue was discovered in Zimbra Collaboration (ZCS) 8.8.15 and 9.0 and 10.0 and 10.1.
Affected: Zimbra Collaboration Suite (Synacor) versions 8.8.15, 8.8.15-p1, 8.8.15-p10, 8.8.15-p11, 8.8.15-p12, 8.8.15-p13, 8.8.15-p14, 8.8.15-p15. The full list is in the CVE brief.
It is exploited in the wild, listed in CISA KEV, Industry KEV feed, CIRCL KEV, ENISA EUVD since Apr 20, 2026.
Yes. It was added on Apr 20, 2026 with a federal remediation due date of Apr 23, 2026.
Public exploit code is available.
Fixed versions are available, including Zimbra Collaboration Suite 10.0.12.
Brandefense priority: patch immediately, because it is listed as exploited in the wild.
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