Applied Cybernetics Group
Threat intel → detection pipeline
Friday, September 18, 2026
Data as of 13:09 UTC

known ransomware use

Synacor Zimbra Collaboration Suite (ZCS) Arbitrary File Upload Vulnerability

Added to KEV
2022-08-11
Federal due date
2022-09-01
Vendor
Synacor
Product
Zimbra Collaboration Suite (ZCS)
EPSS
99.9th percentile (score 0.987, as of 2026-09-16)
NVD CVSS v3.1
7.2 (HIGH)
Ransomware use
Known
Upstream
https://nvd.nist.gov/vuln/detail/CVE-2022-27925

CISA short description

Synacor Zimbra Collaboration Suite (ZCS) contains flaw in the mboximport functionality, allowing an authenticated attacker to upload arbitrary files to perform remote code execution. This vulnerability was chained with CVE-2022-37042 which allows for unauthenticated remote code execution.

Required action

Apply updates per vendor instructions.

NVD description

Zimbra Collaboration (aka ZCS) 8.8.15 and 9.0 has mboximport functionality that receives a ZIP archive and extracts files from it. An authenticated user with administrator rights has the ability to upload arbitrary files to the system, leading to directory traversal.

EPSS percentile is the FIRST.org exploit-probability ranking as of the date noted above; it moves daily. CVSS reflects NVD's analysis at time of publication.