CVE-2025-48700

criticalknown exploitedcovered by 1 sourcefirst seen 2026-04-20

Actively exploited. CVE-2025-48700 is listed in the CISA Known Exploited Vulnerabilities catalog (added 2026-04-20) — exploitation has been observed in the wild, and US federal agencies are required to remediate it under BOD 22-01. Treat patching as urgent.

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.

CSIRTS triage

What: A cross-site scripting vulnerability could allow attackers to execute arbitrary JavaScript within the user's session.
Who is affected: Users of Synacor Zimbra Collaboration Suite (ZCS).
Urgency: Remediation is urgent as the vulnerability is critical and has been exploited.
Action: Update to the latest version of ZCS.

AI-assisted analysis generated from the source advisory — verify against the original.

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Exploitation outlook

Exploitation confirmedAlready exploited in the wild (CISA KEV) — the prediction phase is over. Patch now. Riskier than 75% of all EPSS-scored CVEs.

Advisory coverage (1)

criticalexploitedCVE-2025-48700: Synacor Zimbra Collaboration Suite (ZCS) Cross-site Scripting Vulnerabilitycisa-kev · 2026-04-20

External references

NVD record for CVE-2025-48700

CVE.org record

CISA KEV catalog

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