Libraesva Email Security Gateway Command Injection Vulnerability

[ Why it matters ]Priority signals

• Exploited in the wild: on CISA's Known Exploited Vulnerabilities list since 2025-09-29

[ Description ]Official description

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.

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

[ Fixes ]Fixes and patches

CISA required action (US federal deadline 20 Oct 2025): Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.

No fix or interim patch is linked from our sources yet. Check the vendor references below and limit exposure of affected systems until a fix is available.

[ References ]References

• docs.libraesva.com/knowledgebase/security-advisory-command-injection-vulnerability-cve-…Vendor Advisory
• www.libraesva.com/security-blogVendor Advisory
• www.cisa.gov/known-exploited-vulnerabilities-catalogUS Government Resource