Exploitation evidence
Known exploited · CISA KEV listed
Added 2025-10-07. Ransomware campaign use: Unknown.
CISA 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.
CISA due date: 2025-10-28. This is the catalog’s deadline, not an assessment of your organization’s exposure.
KEV checked 13 Nov 2026, 00:20 Jerusalem · Original catalog ↗Reported products and versions
n/a / n/a
Default status: Not specified
- affected: n/a
Fixes and workarounds
No explicit solution text in the downloaded CVE record. Consult the vendor advisory; unaffected version ranges are shown above as reported, not inferred as a patch recommendation.
Sources and related reporting
CVE Program record ↗ · Download tracked evidence as JSON
- https://wiki.zimbra.com/wiki/Security_Center
- https://wiki.zimbra.com/wiki/Zimbra_Releases/10.1.5#Security_Fixes
- https://wiki.zimbra.com/wiki/Zimbra_Releases/10.0.13#Security_Fixes
- https://wiki.zimbra.com/wiki/Zimbra_Releases/9.0.0/P44#Security_Fixes
- https://strikeready.com/blog/0day-ics-attack-in-the-wild/
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2025-27915
Observed change timeline
History begins when Egret first downloads each source. It is not the complete upstream CVE history.
12 Nov 2026, 18:20 Jerusalem · EPSS observation updated
Stored EPSS snapshot at this observation.
{
"date": "2026-11-12",
"epss": 0.04064,
"percentile": 0.9081
}10 Nov 2026, 18:20 Jerusalem · EPSS observation updated
Stored EPSS snapshot at this observation.
{
"date": "2026-11-10",
"epss": 0.04064,
"percentile": 0.90753
}09 Nov 2026, 18:20 Jerusalem · EPSS observation updated
Stored EPSS snapshot at this observation.
{
"date": "2026-11-09",
"epss": 0.04064,
"percentile": 0.90741
}08 Nov 2026, 18:20 Jerusalem · EPSS observation updated
Stored EPSS snapshot at this observation.
{
"date": "2026-11-08",
"epss": 0.04064,
"percentile": 0.90735
}07 Nov 2026, 18:20 Jerusalem · EPSS observation updated
Stored EPSS snapshot at this observation.
{
"date": "2026-11-07",
"epss": 0.04064,
"percentile": 0.90729
}06 Nov 2026, 18:20 Jerusalem · EPSS observation updated
Stored EPSS snapshot at this observation.
{
"date": "2026-11-06",
"epss": 0.04064,
"percentile": 0.90714
}06 Nov 2026, 06:20 Jerusalem · EPSS observation updated
Stored EPSS snapshot at this observation.
{
"date": "2026-11-05",
"epss": 0.04064,
"percentile": 0.90703
}04 Nov 2026, 18:20 Jerusalem · EPSS observation updated
Stored EPSS snapshot at this observation.
{
"date": "2026-11-04",
"epss": 0.04064,
"percentile": 0.90696
}03 Nov 2026, 18:20 Jerusalem · EPSS observation updated
Stored EPSS snapshot at this observation.
{
"date": "2026-11-03",
"epss": 0.04064,
"percentile": 0.90679
}03 Nov 2026, 18:20 Jerusalem · CVE Program record changed
Stored CNA snapshot at this observation.
{
"containers": {
"adp": [
{
"metrics": [
{
"cvssV3_1": {
"attackComplexity": "LOW",
"attackVector": "NETWORK",
"availabilityImpact": "NONE",
"baseScore": 5.4,
"baseSeverity": "MEDIUM",
"confidentialityImpact": "LOW",
"integrityImpact": "LOW",
"privilegesRequired": "LOW",
"scope": "CHANGED",
"userInteraction": "REQUIRED",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N",
"version": "3.1"
}
},
{
"other": {
"content": {
"id": "CVE-2025-27915",
"options": [
{
"Exploitation": "active"
},
{
"Automatable": "no"
},
{
"Technical Impact": "total"
}
],
"role": "CISA Coordinator",
"timestamp": "2025-10-07T03:55:56.855156Z",
"version": "2.0.3"
},
"type": "ssvc"
}
},
{
"other": {
"content": {
"dateAdded": "2025-10-07",
"reference": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2025-27915"
},
"type": "kev"
}
}
],
"problemTypes": [
{
"descriptions": [
{
"cweId": "CWE-79",
"description": "CWE-79 Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')",
"lang": "en",
"type": "CWE"
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-02-26T19:09:35.780Z",
"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"shortName": "CISA-ADP"
},
"references": [
{
"url": "https://strikeready.com/blog/0day-ics-attack-in-the-wild/"
},
{
"url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2025-27915"
}
],
"timeline": [
{
"lang": "en",
"time": "2025-10-07T00:00:00.000Z",
"value": "CVE-2025-27915 added to CISA KEV"
}
],
"title": "CISA ADP Vulnrichment"
}
],
"cna": {
"affected": [
{
"product": "n/a",
"vendor": "n/a",
"versions": [
{
"status": "affected",
"version": "n/a"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "An issue was discovered in Zimbra Collaboration (ZCS) 9.0 and 10.0 and 10.1. A stored cross-site scripting (XSS) vulnerability exists in the Classic Web Client due to insufficient sanitization of HTML content in ICS files. When a user views an e-mail message containing a malicious ICS entry, its embedded JavaScript executes via an ontoggle event inside a <details> tag. This allows an attacker to run arbitrary JavaScript within the victim's session, potentially leading to unauthorized actions such as setting e-mail filters to redirect messages to an attacker-controlled address. As a result, an attacker can perform unauthorized actions on the victim's account, including e-mail redirection and data exfiltration."
}
],
"problemTypes": [
{
"descriptions": [
{
"description": "n/a",
"lang": "en",
"type": "text"
}
]
}
],
"providerMetadata": {
"dateUpdated": "2025-03-12T14:31:38.012Z",
"orgId": "8254265b-2729-46b6-b9e3-3dfca2d5bfca",
"shortName": "mitre"
},
"references": [
{
"url": "https://wiki.zimbra.com/wiki/Security_Center"
},
{
"url": "https://wiki.zimbra.com/wiki/Zimbra_Releases/10.1.5#Security_Fixes"
},
{
"url": "https://wiki.zimbra.com/wiki/Zimbra_Releases/10.0.13#Security_Fixes"
},
{
"url": "https://wiki.zimbra.com/wiki/Zimbra_Releases/9.0.0/P44#Security_Fixes"
}
]
}
},
"cveMetadata": {
"assignerOrgId": "8254265b-2729-46b6-b9e3-3dfca2d5bfca",
"assignerShortName": "mitre",
"cveId": "CVE-2025-27915",
"datePublished": "2025-03-12T00:00:00.000Z",
"dateReserved": "2025-03-10T00:00:00.000Z",
"dateUpdated": "2026-02-26T19:09:35.780Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2"
}03 Nov 2026, 02:22 Jerusalem · EPSS observation updated
Stored EPSS snapshot at this observation.
{
"date": "2026-11-02",
"epss": 0.04064,
"percentile": 0.90667
}03 Nov 2026, 02:22 Jerusalem · CISA KEV status changed
Stored KEV snapshot at this observation.
{
"cveID": "CVE-2025-27915",
"cwes": [
"CWE-79"
],
"dateAdded": "2025-10-07",
"dueDate": "2025-10-28",
"forensicTriage": "No",
"knownRansomwareCampaignUse": "Unknown",
"notes": "https://wiki.zimbra.com/wiki/Security_Center ; https://nvd.nist.gov/vuln/detail/CVE-2025-27915",
"product": "Zimbra Collaboration Suite (ZCS)",
"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.",
"shortDescription": "Synacor Zimbra Collaboration Suite (ZCS) contains a cross-site scripting vulnerability that exists in the Classic Web Client due to insufficient sanitization of HTML content in ICS files. When a user views an e-mail message containing a malicious ICS entry, its embedded JavaScript executes via an ontoggle event inside a tag. This allows an attacker to run arbitrary JavaScript within the victim's session, potentially leading to unauthorized actions such as setting e-mail filters to redirect messages to an attacker-controlled address. As a result, an attacker can perform unauthorized actions on the victim's account, including e-mail redirection and data exfiltration.",
"vendorProject": "Synacor",
"vulnerabilityName": "Synacor Zimbra Collaboration Suite (ZCS) Cross-site Scripting Vulnerability"
}