CISA KEV · Known exploitedMedium

CVE-2025-59689

Libraesva Email Security Gateway

Libraesva ESG 4.5 through 5.5.x before 5.5.7 allows command injection via a compressed e-mail attachment. For ESG 5.0 a fix has been released in 5.0.31. For ESG 5.1 a fix has been released in 5.1.20. For ESG 5.2 a fix has been released in 5.2.31. For ESG 5.4 a fix has been released in 5.4.8. For ESG 5.5. a fix has been released in 5.5.7.

CVSS: 6.1
EPSS: 1.91%
CISA KEV: Listed
Published: 2025.09.20

PRIORITY ASSESSMENT

Immediate review

CISA has listed this vulnerability in the Known Exploited Vulnerabilities catalog.

Known exploitationConfirmed by CISA KEV

Exploit probability1.91%

Technical severityCVSS 6.1

Vulnerability overview

Affected product and versions

Product: Libraesva Email Security Gateway
Affected versions: 4.5, 5.1, 5.2, 5.3, 5.5, >= 4.5 < 5.0.31, >= 5.1.0 < 5.1.20, >= 5.2.0 < 5.2.31, >= 5.3.0 < 5.3.16, >= 5.4.0 < 5.4.8, >= 5.5.0 < 5.5.7
Fixed versions: 5.0.31, 5.1.20, 5.2.31, 5.3.16, 5.4.8, 5.5.7

Recommended response sequence

Confirm exposure before applying a vendor-supported change.

Full remediation guide

CISA required action

Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.

Due date: 2025.10.20

1
Identify
Confirm that Libraesva Email Security Gateway and an affected version are present.
2
Prioritize
Combine exploitation signals with asset exposure and business criticality.
3
Remediate
Follow the vendor advisory or supported update path and preserve rollback options.
4
Verify
Recheck the version, service health, access paths, and relevant logs.

Technical data

CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
CWE: CWE-77
KEV added: 2025.09.29
Ransomware use: 미확인