CVE-2026-93633

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Source
https://cve.org/CVERecord?id=CVE-2026-93633
Import Source
https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-93633.json
JSON Data
https://api.osv.dev/v1/vulns/CVE-2026-93633
Published
2026-10-23T13:25:21Z
Modified
2026-11-08T02:47:43Z
Severity
  • 5.4 (Medium) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N CVSS Calculator
Summary
Zimbra Collaboration Suite Briefcase CSS Sanitization Bypass via Non-ASCII Stylesheet Characters
Details

A CSS sanitization vulnerability in Zimbra Collaboration Suite (ZCS) allows an authenticated user with Briefcase access to publish a document that displays attacker-controlled content under the Zimbra origin. When processing a stylesheet containing non-ASCII characters, DefangFilter appends the final ASCII segment without sanitizing it. HTML stored as application/x-zimbra-doc can therefore retain CSS URL references that the normal sanitizer removes. An attacker can share a crafted document that loads external resources and displays a credential-collection form using Zimbra's own visual assets. Exploitation requires the victim to open the document in a browser that renders the content type inline; credential theft additionally requires form submission. ZCS 10.1.16 and 10.1.20 are affected.

Database specific 
{
    "cna_assigner": "rapid7",
    "cwe_ids": [
        "CWE-79"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/93xxx/CVE-2026-93633.json",
    "unresolved_ranges": [
        {
            "extracted_events": [
                {
                    "range": [
                        {
                            "last_affected": "10.1.20"
                        }
                    ],
                    "source": "AFFECTED_FIELD",
                    "strategy": "StandardRange"
                }
            ]
        }
    ]
}
References

Affected packages

Git / github.com/zimbra/zm-build

Affected ranges

Type
GIT
Repo
https://github.com/zimbra/zm-build
Events
Introduced
0 Unknown introduced commit / All previous commits are affected
Last Affected
c4837c66360979d757890271f6c976727e71bcad
Database specific
Show details 
{
    "extracted_events": [
        {
            "cpe": "cpe:2.3:a:synacor:zimbra_collaboration_suite:*:*:*:*:*:*:*:*",
            "range": [
                {
                    "introduced": "0"
                },
                {
                    "last_affected": "10.1.20"
                }
            ],
            "source": "CPE_RANGE"
        }
    ]
}

Affected versions

10.*
10.1.0
10.1.1
10.1.10
10.1.13
10.1.14
10.1.16
10.1.20
10.1.4
10.1.5
10.1.6

Database specific

source 
"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-93633.json"

Git / github.com/zimbra/zm-mailbox

Affected ranges

Type
GIT
Repo
https://github.com/zimbra/zm-mailbox
Events
Introduced
0 Unknown introduced commit / All previous commits are affected
Last Affected
c80d2bbf562968d44fa90edd843f1985026585c3
Database specific
Show details 
{
    "extracted_events": [
        {
            "cpe": "cpe:2.3:a:synacor:zimbra_collaboration_suite:*:*:*:*:*:*:*:*",
            "range": [
                {
                    "introduced": "0"
                },
                {
                    "last_affected": "10.1.20"
                }
            ],
            "source": "CPE_RANGE"
        }
    ]
}

Affected versions

10.*
10.1.0
10.1.1
10.1.10
10.1.13
10.1.14
10.1.16
10.1.17
10.1.18
10.1.2
10.1.20
10.1.3
10.1.4
10.1.5
10.1.6
10.1.7
10.1.8
8.*
8.8.11

Database specific

source 
"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-93633.json"