RCE in Libraesva Email Security Gateway

CVE-2025-59689

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…

Vulnerability class: Command Injection (OS Command Injection)

EPSS: 0.060 (90.9th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 6.1 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N.

Affected products

Weakness classification (CWE)

CISA KEV (Known Exploited Vulnerabilities)

This CVE is on the CISA KEV catalog, added on . CISA KEV inclusion means CISA has confirmed in-the-wild exploitation; US federal agencies are required to remediate within a published due date.

BOD 22-01 due date: .

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.

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2025-59689?
CVE-2025-59689 is a medium-severity vulnerability in Libraesva Email Security Gateway, classified under Command Injection. CVSS score: 6.1/10. Published 2025-09-19.
How severe is CVE-2025-59689?
Medium severity. CVSS v3 base score is 6.1 out of 10.
Is CVE-2025-59689 known to be exploited?
Yes. CVE-2025-59689 is listed in the CISA Known Exploited Vulnerabilities catalog (added 2025-09-29), indicating it is being actively exploited. 4 public proof-of-concept repositories are indexed.