How severe is CVE-2025-48700?

CVE-2025-48700 has a CVSS score of 6.1/10, rated MEDIUM. Review your exposure and patch according to your risk tolerance.

Which packages are affected by CVE-2025-48700?

Affected package information for CVE-2025-48700 is not yet fully mapped. Check the official advisory links for details.

How do I fix CVE-2025-48700?

No fixed version has been published for CVE-2025-48700 yet. Monitor the advisory for updates, apply mitigations recommended by the vendor, and use O3 Security to track when a fix becomes available in your stack.

Is CVE-2025-48700 actively exploited in the wild?

No public exploit code has been indexed for CVE-2025-48700 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for CVE-2025-48700?

CVE-2025-48700 has an EPSS (Exploit Prediction Scoring System) score of 18.2%, placing it in the 95th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score warrants monitoring and prompt remediation.

Is CVE-2025-48700 in the CISA Known Exploited Vulnerabilities catalog?

Yes. CVE-2025-48700 (Synacor Zimbra Collaboration Suite (ZCS) Cross-site Scripting Vulnerability) was added to CISA's Known Exploited Vulnerabilities (KEV) catalog on 2026-04-20. CISA required all US federal civilian agencies to remediate this vulnerability by 2026-04-23. The required action was: Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable. Being listed in the KEV catalog is the strongest possible confirmation of active exploitation — treat this as a critical priority.

When was CVE-2025-48700 published, and has it been updated?

CVE-2025-48700 was published on June 23, 2025 and was last updated on April 12, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

CVE-2025-48700: Cross-Site Scripting (Medium 6.1)

EPSS Exploitation Probability

via FIRST.org ↗

18.2%probability of exploitation in next 30 days

Moderate Risk95th percentile0.00%

EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.

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.

Frequently Asked Questions

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, req

O3 Security · Impact-Aware SCA

Is CVE-2025-48700 in your stack?

O3 detects CVE-2025-48700 across dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.

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