---
id: "CVE-2022-27924"
kind: "vulnerability"
aliases: ["CVE-2022-27924"]
title: "synacor zimbra collaboration suite: Zimbra Collaboration (aka ZCS) 8.8.15 and 9.0 allows an unauthenticated attacker to inject arbitrary memcache\u2026"
severity: "critical"
cvss: 9.8
epss: 0.93908
exploited: true
status: "open"
category: "package"
products: [{"name": "Synacor Zimbra Collaboration Suite (ZCS)", "fixed": [], "affected": "", "ecosystem": "vendor"}, {"name": "synacor zimbra collaboration suite", "fixed": [], "affected": "= 8.8.15", "ecosystem": "vendor"}, {"name": "synacor zimbra collaboration suite", "fixed": [], "affected": "= 9.0.0", "ecosystem": "vendor"}]
ecosystems: ["vendor"]
tags: ["email", "exploited", "package", "ransomware", "self-hosted", "zimbra"]
not_affected_if: ["managed-hosting"]
published_at: "2022-04-21T00:15:08+00:00"
first_seen_at: "2026-10-23T19:11:52+00:00"
updated_at: "2026-10-23T22:29:04+00:00"
sources: [{"source": "kev", "url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog?search_api_fulltext=CVE-2022-27924", "first_seen_at": "2026-10-23T19:11:52+00:00"}, {"source": "epss", "url": "https://api.first.org/data/v1/epss?cve=CVE-2022-27924", "first_seen_at": "2026-10-23T19:13:45+00:00"}, {"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2022-27924", "first_seen_at": "2026-10-23T22:29:04+00:00"}]
---

# synacor zimbra collaboration suite: Zimbra Collaboration (aka ZCS) 8.8.15 and 9.0 allows an unauthenticated attacker to inject arbitrary memcache…

Zimbra Collaboration Suite lets an attacker inject memcache commands into a running instance, overwriting arbitrary cached entries. CISA lists it as actively exploited, and ransomware use is tagged in the source data.

_Summary, check and fix written by a model from the sources; labelled as such._

## Affected

- vendor:Synacor Zimbra Collaboration Suite (ZCS) affected ? fixed ?
- vendor:synacor zimbra collaboration suite affected = 8.8.15 fixed ?
- vendor:synacor zimbra collaboration suite affected = 9.0.0 fixed ?

## Fix

Apply the Zimbra updates per vendor instructions; the specific fixed version is not stated in the sources.

## Timeline

- 2026-10-23T19:11:52+00:00 kev https://www.cisa.gov/known-exploited-vulnerabilities-catalog?search_api_fulltext=CVE-2022-27924
- 2026-10-23T19:13:45+00:00 epss https://api.first.org/data/v1/epss?cve=CVE-2022-27924
- 2026-10-23T22:29:04+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2022-27924

## From the sources

Zimbra Collaboration (aka ZCS) 8.8.15 and 9.0 allows an unauthenticated attacker to inject arbitrary memcache commands into a targeted instance. These memcache commands becomes unescaped, causing an overwrite of arbitrary cached entries.

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_Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai_