CVE-2026-115786Published

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

Exact source revision recorded 23 Oct 2026 16:01:20 UTC. It does not establish the source's current position. Latest evidence.

Recorded JSON

cve-program · CVE-2026-115786

Published

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.

Source published: 23 Oct 2026 13:53:33 UTC
Source modified: 23 Oct 2026 13:53:33 UTC
Observed here: 23 Oct 2026 16:01:20 UTC
Source terms: CVE Program Terms of Use

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CVSS 3.1 · 6.5 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H