{"id":"CVE-2025-48700","published":"2025-06-23T15:15:27Z","modified":"2026-06-17T09:30:11Z","title":"Synacor Zimbra Collaboration Suite (ZCS) Cross-site Scripting Vulnerability","vendor":"Synacor","product":"Zimbra Collaboration Suite (ZCS)","tier":"core","eol":null,"description":{"text":"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.","provenance":"source","from":"NVD"},"summary":{"text":"Synacor Zimbra Collaboration Suite (ZCS) contains a cross-site scripting flaw in the Classic UI, caused by insufficient sanitization of HTML content such as crafted tag structures and attribute values that include an @import directive and other script injection vectors. An unauthenticated remote attacker can send a crafted e-mail message that, when viewed by a user in the Classic UI, executes arbitrary JavaScript within that user's session and may expose sensitive information, with no further user interaction beyond viewing the message.","provenance":"ai","model":"claude-haiku-5-5","generatedAt":"2026-10-23T07:14:47Z"},"cvss":{"score":6.1,"severity":"MEDIUM","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N","provenance":"source","from":"NVD"},"epss":{"score":0.01713,"percentile":0.77321,"date":"2026-10-29","provenance":"source"},"kev":{"dateAdded":"2026-04-20","dueDate":"2026-04-23","ransomware":false,"requiredAction":"Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.","notes":"https://wiki.zimbra.com/wiki/Zimbra_Security_Advisories ; https://nvd.nist.gov/vuln/detail/CVE-2025-48700","provenance":"source"},"vulncheckKev":{"dateAdded":"2026-04-20","exploitedFirstSeen":"2026-04-20","ransomware":false,"evidence":[{"url":"https://www.cisa.gov/sites/default/files/feeds/known_exploited_vulnerabilities.json","date":"2026-04-20"},{"url":"https://www.crowdstrike.com/explore/crowdstrike-content/crowdstrike-2026-technology-threat-landscape-report","date":"2026-06-09"}],"evidenceTotal":2,"provenance":"source"},"exploited":true,"otx":{"pulseCount":50,"pulses":[{"name":"Actively_Exploited_Kev | Oct 30, 2026","url":"https://otx.alienvault.com/pulse/6ae35d889ea92b4ce19c2680","created":"2026-10-29"},{"name":"Actively_Exploited_Kev | Oct 29, 2026","url":"https://otx.alienvault.com/pulse/6ae20c1db17e7057ae7d9ad1","created":"2026-10-28"},{"name":"Actively_Exploited_Kev | Oct 28, 2026","url":"https://otx.alienvault.com/pulse/6ae0ba7e0e2a97ff7b218819","created":"2026-10-27"},{"name":"Actively_Exploited_Kev | Oct 27, 2026","url":"https://otx.alienvault.com/pulse/6adf68b85c3e852f3c111d18","created":"2026-10-26"},{"name":"Actively_Exploited_Kev | Oct 24, 2026","url":"https://otx.alienvault.com/pulse/6adb740e397c3ad4799aa4cd","created":"2026-10-23"},{"name":"Actively_Exploited_Kev | Oct 23, 2026","url":"https://otx.alienvault.com/pulse/6ada236fcfba2dfa730ea482","created":"2026-10-22"},{"name":"Actively_Exploited_Kev | Oct 22, 2026","url":"https://otx.alienvault.com/pulse/6ad8d33a077cbb5cab524d80","created":"2026-10-21"},{"name":"Actively_Exploited_Kev | Oct 21, 2026","url":"https://otx.alienvault.com/pulse/6ad78130c4d1ac2be83a8b6d","created":"2026-10-20"},{"name":"Actively_Exploited_Kev | Oct 20, 2026","url":"https://otx.alienvault.com/pulse/6ad62f63c24a405a3423cc13","created":"2026-10-19"},{"name":"Actively_Exploited_Kev | Oct 19, 2026","url":"https://otx.alienvault.com/pulse/6ad4dda174e5797d0bd238b7","created":"2026-10-18"}],"provenance":"machine"},"cwes":[{"id":"CWE-79","name":"Improper Neutralization of Input During Web Page Generation"}],"references":[{"url":"https://wiki.zimbra.com/wiki/Security_Center","tags":["Release Notes"]},{"url":"https://wiki.zimbra.com/wiki/Zimbra_Responsible_Disclosure_Policy","tags":["Product"]},{"url":"https://wiki.zimbra.com/wiki/Zimbra_Security_Advisories","tags":["Vendor Advisory"]},{"url":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2025-48700","tags":["US Government Resource"]}],"techniques":[{"id":"T1566.002","name":"Spearphishing Link","tactics":["initial-access"],"provenance":"ai","basis":"ai-mapping","bases":["ai-mapping"],"basisDetail":"claude-haiku-5-5: Malicious email delivered to victim triggers exploit","mappingType":"exploitation_technique","evidence":[{"from":"description","quote":"triggered when a user views a crafted e-mail message","start":525,"end":577}],"model":"claude-haiku-5-5","confidence":"medium","confidenceNote":"AI-mapped from the description (quote-validated, not expert-reviewed)"},{"id":"T1056","name":"Input Capture","tactics":["collection","credential-access"],"provenance":"ai","basis":"ai-mapping","bases":["ai-mapping"],"basisDetail":"claude-haiku-5-5: XSS in session enables input/data capture","mappingType":"primary_impact","evidence":[{"from":"description","quote":"potentially leading to unauthorized access to sensitive information","start":232,"end":299}],"model":"claude-haiku-5-5","confidence":"medium","confidenceNote":"AI-mapped from the description (quote-validated, not expert-reviewed)"},{"id":"T1059.007","name":"JavaScript","tactics":["execution"],"provenance":"ai","basis":"ai-mapping","bases":["ai-mapping"],"basisDetail":"claude-haiku-5-5: Arbitrary JavaScript execution in browser session","mappingType":"primary_impact","evidence":[{"from":"description","quote":"execute arbitrary JavaScript within the user's session","start":176,"end":230}],"model":"claude-haiku-5-5","confidence":"medium","confidenceNote":"AI-mapped from the description (quote-validated, not expert-reviewed)"}],"reports":[],"affected":[],"advisories":[],"euvd":{"id":"EUVD-2025-18891","url":"https://euvd.enisa.europa.eu/vulnerability/EUVD-2025-18891","exploited":true,"exploitedSince":"2026-04-20","provenance":"source"},"exploits":[],"exploitSources":null,"exploitRefs":[],"flow":[{"stage":"exploitation","techniques":["T1566.002"],"provenance":"ai"},{"stage":"primary","techniques":["T1059.007","T1056"],"provenance":"ai"}],"timeline":[{"date":"2025-06-23","kind":"published","label":"Published (NVD)","url":"https://nvd.nist.gov/vuln/detail/CVE-2025-48700","provenance":"source"},{"date":"2026-04-20","kind":"exploited-reported","label":"Exploitation first reported (VulnCheck KEV evidence)","url":"https://www.cisa.gov/sites/default/files/feeds/known_exploited_vulnerabilities.json","provenance":"source"},{"date":"2026-04-20","kind":"kev","label":"Added to CISA KEV","url":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","provenance":"source"},{"date":"2026-04-20","kind":"euvd-exploited","label":"ENISA EUVD: exploited","url":"https://euvd.enisa.europa.eu/vulnerability/EUVD-2025-18891","provenance":"source"}],"speed":{"daysToPublicExploit":null,"firstExploitFrom":null,"daysToKev":301},"priority":{"score":62.7,"factors":[{"name":"In a KEV catalog","points":35.0,"detail":"listed in CISA KEV and VulnCheck KEV"},{"name":"Recent KEV listing","points":5.0,"detail":"added 193 days ago"},{"name":"Known ransomware use","points":0.0,"detail":"not known"},{"name":"EPSS percentile","points":15.46,"detail":"percentile 0.7732"},{"name":"Named in threat reports","points":0.0,"detail":"0 reports"},{"name":"Public exploit code","points":0.0,"detail":"none found"},{"name":"Mentioned in OTX pulses","points":3.0,"detail":"50 pulses"},{"name":"CVSS severity","points":4.27,"detail":"base score 6.1"},{"name":"End-of-life product","points":0.0,"detail":"supported or unknown"}]},"lineage":{"familyId":"fam-class-synacor-zimbra-collaboration-suite-zcs-cwe-79"}}