CVE-2026-93638
Full vulnerability record from the local CVENow database.
Description
A reflected cross-site scripting vulnerability in the login page of Zimbra Collaboration Suite (ZCS) allows an unauthenticated attacker to execute JavaScript through the zrememberme parameter. A crafted relogin URL selects a two-factor error display that inserts the parameter into a hidden input attribute without HTML encoding. A victim who opens the URL receives attacker-controlled script and page content under the legitimate Zimbra origin, allowing credential capture through a replacement login form. The relogin path logs out an existing session before rendering the payload, so the demonstrated attack does not inherit that session's mailbox access. ZCS 10.1.16 and 10.1.17 are affected.
View original CVE JSON
{
"id": "CVE-2026-93638",
"sourceIdentifier": "[email protected]",
"published": "2026-10-23T14:17:57.517",
"lastModified": "2026-10-28T21:13:14.840",
"vulnStatus": "Analyzed",
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "A reflected cross-site scripting vulnerability in the login page of Zimbra Collaboration Suite (ZCS) allows an unauthenticated attacker to execute JavaScript through the zrememberme parameter. A crafted relogin URL selects a two-factor error display that inserts the parameter into a hidden input attribute without HTML encoding. A victim who opens the URL receives attacker-controlled script and page content under the legitimate Zimbra origin, allowing credential capture through a replacement login form. The relogin path logs out an existing session before rendering the payload, so the demonstrated attack does not inherit that session's mailbox access. ZCS 10.1.16 and 10.1.17 are affected."
}
],
"affected": [
{
"source": "[email protected]",
"affectedData": [
{
"vendor": "Zimbra",
"product": "Zimbra Collaboration Suite",
"defaultStatus": "unaffected",
"versions": [
{
"version": "0",
"lessThanOrEqual": "10.1.17",
"versionType": "semver",
"status": "affected"
}
]
}
]
}
],
"metrics": {
"cvssMetricV31": [
{
"source": "[email protected]",
"type": "Secondary",
"cvssData": {
"version": "3.1",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N",
"baseScore": 6.1,
"baseSeverity": "MEDIUM",
"attackVector": "NETWORK",
"attackComplexity": "LOW",
"privilegesRequired": "NONE",
"userInteraction": "REQUIRED",
"scope": "CHANGED",
"confidentialityImpact": "LOW",
"integrityImpact": "LOW",
"availabilityImpact": "NONE"
},
"exploitabilityScore": 2.8,
"impactScore": 2.7
}
],
"ssvcV203": [
{
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"ssvcData": {
"timestamp": "2026-10-28T17:49:21.564825Z",
"id": "CVE-2026-93638",
"options": [
{
"exploitation": "none"
},
{
"automatable": "no"
},
{
"technicalImpact": "partial"
}
],
"role": "CISA Coordinator",
"version": "2.0.3"
}
}
]
},
"weaknesses": [
{
"source": "[email protected]",
"type": "Secondary",
"description": [
{
"lang": "en",
"value": "CWE-79"
}
]
}
],
"configurations": [
{
"nodes": [
{
"operator": "OR",
"negate": false,
"cpeMatch": [
{
"vulnerable": true,
"criteria": "cpe:2.3:a:synacor:zimbra_collaboration_suite:*:*:*:*:*:*:*:*",
"versionEndIncluding": "10.1.17",
"matchCriteriaId": "CED568B6-824F-48AB-A518-EA79A1610341"
}
]
}
]
}
],
"references": [
{
"url": "https://wiki.zimbra.com/wiki/Zimbra_Security_Advisories",
"source": "[email protected]",
"tags": [
"Vendor Advisory"
]
},
{
"url": "https://www.rapid7.com/blog/post/ve-breaking-zimbra-identity-boundaries-part-1/",
"source": "[email protected]",
"tags": [
"Exploit",
"Third Party Advisory"
]
}
]
}