CVE-2026-93639
Full vulnerability record from the local CVENow database.
Description
A missing authorization vulnerability in Zimbra Collaboration Suite (ZCS) allows a delegated administrator with no explicit administrative grants to overwrite global Zimlet configuration through ConfigureZimletRequest. The uploaded configuration can also add an attacker-controlled domain to the proxy allowlist of the default class of service. If a signed-in user in that class opens a crafted /service/proxy URL, Zimbra serves attacker-controlled HTML under its own origin. The resulting JavaScript can read mailbox data and perform authenticated actions as the victim. Exploitation requires a delegated-administrator account and access to the admin SOAP service; the browser compromise additionally requires the victim to open the crafted URL. ZCS 10.1.16 and 10.1.20 are affected.
View original CVE JSON
{
"id": "CVE-2026-93639",
"sourceIdentifier": "[email protected]",
"published": "2026-10-23T14:17:57.640",
"lastModified": "2026-10-28T20:18:53.563",
"vulnStatus": "Undergoing Analysis",
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "A missing authorization vulnerability in Zimbra Collaboration Suite (ZCS) allows a delegated administrator with no explicit administrative grants to overwrite global Zimlet configuration through ConfigureZimletRequest. The uploaded configuration can also add an attacker-controlled domain to the proxy allowlist of the default class of service. If a signed-in user in that class opens a crafted /service/proxy URL, Zimbra serves attacker-controlled HTML under its own origin. The resulting JavaScript can read mailbox data and perform authenticated actions as the victim. Exploitation requires a delegated-administrator account and access to the admin SOAP service; the browser compromise additionally requires the victim to open the crafted URL. ZCS 10.1.16 and 10.1.20 are affected."
}
],
"affected": [
{
"source": "[email protected]",
"affectedData": [
{
"vendor": "Zimbra",
"product": "Zimbra Collaboration Suite",
"defaultStatus": "unaffected",
"versions": [
{
"version": "0",
"lessThanOrEqual": "10.1.20",
"versionType": "semver",
"status": "affected"
}
]
}
]
}
],
"metrics": {
"cvssMetricV31": [
{
"source": "[email protected]",
"type": "Secondary",
"cvssData": {
"version": "3.1",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N",
"baseScore": 8.7,
"baseSeverity": "HIGH",
"attackVector": "NETWORK",
"attackComplexity": "LOW",
"privilegesRequired": "LOW",
"userInteraction": "REQUIRED",
"scope": "CHANGED",
"confidentialityImpact": "HIGH",
"integrityImpact": "HIGH",
"availabilityImpact": "NONE"
},
"exploitabilityScore": 2.3,
"impactScore": 5.8
}
],
"ssvcV203": [
{
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"ssvcData": {
"timestamp": "2026-10-28T17:53:42.532170Z",
"id": "CVE-2026-93639",
"options": [
{
"exploitation": "none"
},
{
"automatable": "no"
},
{
"technicalImpact": "total"
}
],
"role": "CISA Coordinator",
"version": "2.0.3"
}
}
]
},
"weaknesses": [
{
"source": "[email protected]",
"type": "Secondary",
"description": [
{
"lang": "en",
"value": "CWE-862"
}
]
}
],
"references": [
{
"url": "https://wiki.zimbra.com/wiki/Zimbra_Security_Advisories",
"source": "[email protected]"
},
{
"url": "https://www.rapid7.com/blog/post/ve-breaking-zimbra-identity-boundaries-part-1/",
"source": "[email protected]"
}
]
}