CVE-2025-59689
MediumExploitedPublic exploitLibraesva ESG 4.5 through 5.5.x before 5.5.7 allows command injection via a compressed e-mail attachment.
Published Sep 19, 2025 · Updated Feb 26, 2026
Key Facts
Patch immediately- CVE-2025-59689 is a medium-severity vulnerability (CVSS 6.1 v3.1) affecting Email Security Gateway (Libraesva).
- It is exploited in the wild, listed in CISA KEV, Industry KEV feed, CIRCL KEV, ENISA EUVD since Sep 22, 2025. Public exploit code is available.
- EPSS estimates a 1.9% probability of exploitation in the next 30 days.
- Fixed versions are available, including Email Security Gateway 5.0.31, Email Security Gateway 5.1.20, Email Security Gateway 5.2.31.
- Brandefense priority: patch immediately, because it is listed as exploited in the wild.
CVSS v3.1
6.1
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
EPSS (30-day exploit likelihood)
1.9%
Higher than 78.9% of all scored CVEs
Exploited in the wild
Yes
4 catalog listings
Public exploit code
Available
Proof-of-concept or weaponized module
Get the full CVE-2025-59689 brief as a PDF
Every affected product and fixed release, exploitation status and a first 24 hours response checklist, emailed within minutes.
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.
Known-Exploited Catalog Listings
| Catalog | Added | Remediation due | Ransomware use |
|---|---|---|---|
| CISA KEV | Sep 29, 2025 | Oct 20, 2025 | Not reported |
| Industry KEV feed | Sep 22, 2025 | Oct 20, 2025 | Not reported |
| CIRCL KEV | Sep 29, 2025 | Oct 20, 2025 | Not reported |
| ENISA EUVD | Sep 29, 2025 | n/a | Not reported |
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.
Affected Products
2 affected entries in total| Product | Affected versions | Fixed in |
|---|---|---|
| Email Security GatewayLibraesva | >= 4.5 | 5.0.31 |
Patched Releases
Email Security Gateway
5.0.31, 5.1.20, 5.2.31, 5.4.8, 5.5.7
Timeline
Publicly disclosed
Sep 19, 2025
Added to Industry KEV feed
Sep 22, 2025
Added to CISA KEV
Sep 29, 2025
Added to CIRCL KEV
Sep 29, 2025
Added to ENISA EUVD
Sep 29, 2025
Last updated
Feb 26, 2026
Weakness Type
- CWE-77 Improper Neutralization of Special Elements used in a Command ('Command Injection')
References
- advisoryVulnCheck exploitation report
- advisoryhttps://www.libraesva.com/security-blog/
- exploitVulnCheck exploitation report
- exploitVulnCheck exploitation report
- exploitVulnCheck exploitation report
FAQ
Common Questions.
Libraesva ESG 4.5 through 5.5.x before 5.5.7 allows command injection via a compressed e-mail attachment.
Affected: Email Security Gateway (Libraesva) versions >= 4.5. The full list is in the CVE brief.
It is exploited in the wild, listed in CISA KEV, Industry KEV feed, CIRCL KEV, ENISA EUVD since Sep 22, 2025.
Yes. It was added on Sep 29, 2025 with a federal remediation due date of Oct 20, 2025.
Public exploit code is available.
Fixed versions are available, including Email Security Gateway 5.0.31, Email Security Gateway 5.1.20, Email Security Gateway 5.2.31.
Brandefense priority: patch immediately, because it is listed as exploited in the wild.
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