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Zimbra Collaboration Suite Shared-File Mailbox Quota Accounting Error Enables Quota Exhaustion

Type: advisorySource: Official CVE List1 source record

A mailbox quota-accounting vulnerability in Zimbra Collaboration Suite (ZCS) allows an authenticated user to consume another user’s mailbox quota by repeatedly sharing and revoking a document. Creation of the recipient’s shared-file record charges the document size to mailbox-wide usage. Revocation deletes the record and reverses its folder counters without reversing the mailbox-wide charge. Repeated normal share notifications therefore accumulate quota usage after the visible records are gone. On accounts with a finite quota, this can prevent incoming mail and other size-increasing operations without recipient interaction. The issue affects ZCS 10.1.16 and 10.1.20.

Announced Source revision 1
Original source ↗

CVE-2026-115786

Primary source · Revision 1

Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.

Security context

Source reference: cve:CVE-2026-115786

Zimbra Collaboration Suite

Source reference: /containers/cna/affected/0/product

Affected versions
Not stated in this record
Fixed versions
Not stated in this record
Prerequisites
Not stated in this record

Structured affected-version data

Original package identities and version rules from this source.

[
  {
    "vendor": "Zimbra",
    "product": "Zimbra Collaboration Suite",
    "versions": [
      {
        "status": "affected",
        "version": "0",
        "versionType": "semver",
        "lessThanOrEqual": "10.1.20"
      }
    ],
    "defaultStatus": "unaffected"
  }
]
Related CVEs
CVE-2026-115786

Source reference: /cveMetadata/cveId

Publisher severity

medium

Source reference: /containers/cna/metrics

Event
#52959 · Revision 1
Added to Heist Feed
Publisher date
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