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Weekly Signal
Live intelligence Updated 20 Aug 2026 · 01:51 UTC

Synacor · Zimbra Collaboration Suite, Zimbra Collaboration Suite (ZCS)

CVE-2024-45519

Synacor Zimbra Collaboration Suite (ZCS) Command Execution Vulnerability

Recommended action

Treat this as an immediate remediation priority. Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.

View response plan
CVSS9.8
EPSS99.9%
KEVYes
ExploitationConfirmed exploitation
PatchPatch or guidance available ↓

Assessment

Why it matters

CISA lists this vulnerability as known to be exploited; exploitation is confirmed; EPSS is 99.9%; technical severity is CVSS 9.8.

The postjournal service in Zimbra Collaboration (ZCS) before 8.8.15 Patch 46, 9 before 9.0.0 Patch 41, 10 before 10.0.9, and 10.1 before 10.1.1 sometimes allows unauthenticated users to execute commands.

Who should care

  • Teams operating Zimbra Collaboration Suite, Zimbra Collaboration Suite (ZCS)
  • Vulnerability and exposure management teams
  • Security operations teams monitoring exploitation activity

Response plan

What I would do

  1. Confirm whether Zimbra Collaboration Suite, Zimbra Collaboration Suite (ZCS) is present in the environment.
  2. Identify affected versions and establish whether vulnerable services are exposed or reachable.
  3. Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.
  4. Review relevant security telemetry for evidence of attempted or successful exploitation.
  5. Document the remediation decision and track it to verified completion.

Vendor remediation

Patch and remediation links

Use the vendor source below to confirm the correct fixed version, package or mitigation for your affected product.

Technical details

CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CWE
CWE-284
Affected versions
Synacor Zimbra Collaboration Suite (Version: 10.1.0); Synacor Zimbra Collaboration Suite (ZCS)
Published
2 October 2024
Attack vector
Network
Privileges required
None
User interaction
None

Signal timeline

  1. Added to CISA KEV
  2. Latest EPSS score: 99.9%
  3. Signal calculated at 85

External references

Live public intelligence This assessment combines public-source evidence. Validate the affected product, version and exposure against your own environment before making a risk decision.