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CVE-2026-93634

medium

A cross-account authorization vulnerability in Zimbra Collaboration Suite (ZCS) allows an authenticated user to insert forged shared-file records into another…

Vendor / product: Synacor — zimbra collaboration suite

A cross-account authorization vulnerability in Zimbra Collaboration Suite (ZCS) allows an authenticated user to insert forged shared-file records into another user's mailbox through FileSharedWithMeRequest. The request bypasses delegated-account authorization and accepts attacker-selected file metadata, owner identifiers and declared sizes without validating a corresponding document share. An attacker can plant entries attributed to another real local account without that account sharing a document. No victim interaction is required. ZCS 10.1.16 and 10.1.20 are affected.

CVSS
4.3
4.3 (CVSS v3.1)
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N
Severity source: NVD CVSS v3.1 (cve@rapid7.com)
Timeline (UTC)
Published: 2026-10-23 14:17
Modified: 2026-10-28 21:21
NVD status: Analyzed
Last synced 10 hours ago
Verified against the source API 2026-10-28 22:10 UTC
Exploitation
Not listed in CISA KEV (as of last catalog sync)
Absence from KEV does not mean a CVE is not exploited. Exploitation status: unknown (no authoritative evidence in our sources).

Affected products

synacor / zimbra_collaboration_suite ≤10.1.20

Weakness classification (CWE)

CWE-639

Source: NVD / CISA. “NVD-CWE-Other” and “NVD-CWE-noinfo” mean NVD could not assign a specific weakness.

Mitigation & advisories

Vendor advisory: https://wiki.zimbra.com/wiki/Zimbra_Security_Advisories

References

Data sources

NVD CVE API 2.0 — fetched 2026-10-28 22:10 UTC · record ↗

Learn the basics

Understanding CVEs and CVSS Scores

Related CVEs

CVE-2026-93631CVE-2026-93633CVE-2026-93636CVE-2026-93638CVE-2025-66376