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.

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 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.

Vulnerability class: Command Injection (OS Command Injection)

Published 2025-09-19 · last modified 2026-06-17.

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.

EPSS exploit prediction

EPSS: 0.019 (78.9th percentile), scored 2026-10-19.

Low probability of exploitation in the next 30 days, but still tracked. 79th percentile — 78.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.019 · newest: 0.019 · change: 0.000

Affected products

Libraesva Email Security Gateway — versions 4.5, 5.1, 5.2
Libraesva Email Security Gateway

Weakness classification (CWE)

CWE-77 — Command Injection

CISA KEV (Known Exploited Vulnerabilities)

This CVE is on the CISA KEV catalog, added on 2025-09-29. 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: 2025-10-20.

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

www.libraesva.com/security-blog/ (Vendor Advisory)
docs.libraesva.com/knowledgebase/security-advisory-command-injection-vulnerabil… (Vendor Advisory)
134c704f-9b21-4f2e-91b3-4a467353bcc0 (US Government Resource)

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.