IRONSMITHINTEL
MEDIUMCVSS6.1
|
Actively Exploited
|CISA KEV|CVE-2025-59689|Auth: none — unauthenticated|Reboot: required|Manual only

Libraesva Email Security Gateway Command Injection Vulnerability

Libraesva Email Security Gateway (ESG) contains a command injection vulnerability which allows command injection via a compressed e-mail attachment.

Published Sep 19, 2025 · Updated May 16, 2026
Why patchRisk explained in plain English
Worst-case scenarioIf unpatched

A remote attacker, without authentication, can achieve partial data exposure, partial data tampering. Federal agencies are required to remediate by 2025-10-20 under CISA BOD 22-01.

How the attack worksNo clicks needed

This is a Command Injection (CWE-77) vulnerability in 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. Exploitation requires remote network access, low attack complexity, no authentication required, and user interaction required.

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Phishing link

→

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Malicious file

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Server compromised

Am I affected?Quick check

Probably yes if any of these apply:

●IT Security
●Running email security gateway: 4.5 ≤ v < 5.0.31, 5.1.0 ≤ v < 5.1.20, 5.2.0 ≤ v < 5.2.31, 5.3.0 ≤ v < 5.3.16, 5.4.0 ≤ v < 5.4.8, 5.5.0 ≤ v < 5.5.7
Real-world incidentsWhat we've seen

CISA added this CVE to the Known Exploited Vulnerabilities catalog on 2025-09-29 based on evidence of active exploitation in the wild. Federal agencies required to remediate by 2025-10-20.

How to patch

Manual remediation steps

Apply the Vendor Patch

This vulnerability is in the CISA Known Exploited Vulnerabilities catalog — apply the vendor's security update as soon as possible.

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.

References

    1
    Vendor advisory: https://docs.libraesva.com/knowledgebase/security-advisory-command-injection-vulnerability-cve-2025-59689/
    1
    NVD entry: https://nvd.nist.gov/vuln/detail/CVE-2025-59689
    1
    CISA KEV: https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2025-59689
PowerShell automationComing soon

No tested PowerShell script for this entry yet. We’re prioritising automation based on user demand.

References

↗ CVE-2025-59689↗ NVD↗ Vendor Advisory