Security Digest · Vulnerability record · Known exploited
CVE-2025-59689: Libraesva Email Security Gateway Command Injection Vulnerability
Exploited in the wild (CISA KEV). Libraesva ESG 4.5 through 5.5.x before 5.5.7 allows command injection via a compressed e-mail attachment.
CISA KEV · added 2025-09-29 CVSS 6.1 Medium EPSS 1.9% · p79
Should you act?
Exploited: patch now if you run it
CISA has confirmed exploitation in the wild. This signal is computed from CISA KEV, EPSS and CVSS data; it is not an editorial verdict.
- Yes, if you run Libraesva Email Security Gateway. CISA added this CVE to its Known Exploited Vulnerabilities catalog on 2025-09-29, which means there is reliable evidence of exploitation in the wild. US federal agencies must remediate by 2025-10-20; treat that as the outer limit, not the target.
- EPSS 1.9%, percentile 79: FIRST’s model estimates a 1.9% chance of exploitation activity in the next 30 days, higher than 79% of all scored CVEs (moderate). EPSS is a probability, not a verdict.
- Needs a user to click or open something. Phishing makes that realistic, but it is not wormable.
What it is
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’s summary
Libraesva Email Security Gateway (ESG) contains a command injection vulnerability which allows command injection via a compressed e-mail attachment.
Weakness type: CWE-77.
Product: Libraesva Email Security Gateway · Assigned by: mitre · Published: 2025-09-19
Affected and fixed versions
| Vendor | Product | Affected versions (per CVE record) |
|---|---|---|
| Libraesva | Email Security Gateway | 4.5 < 5.0.31, 5.1 < 5.1.20, 5.2 < 5.2.31, 5.3 < 5.4.8, 5.5 < 5.5.7 |
Severity scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| mitre | 3.1 | 6.1 Medium | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N |
- Attack vector: network (remotely reachable)
- Attack complexity: low
- Privileges required: none (no login)
- User interaction: required (a user must click/open something)
- Scope: changed (can affect other components)
CVSS measures how bad a flaw is if exploited, not how likely exploitation is. Read it next to the exploitation data below.
Exploitation and urgency
- CISA KEV: added 2025-09-29; federal due date 2025-10-20. Known ransomware use: Unknown.
- 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.
- CISA SSVC assessment: exploitation active, automatable no, technical impact total.
- FIRST EPSS (model of 2026-10-21): 1.86% probability of exploitation activity in the next 30 days; percentile 79.
Timeline
- — CVE record published by mitre
- — Added to CISA’s Known Exploited Vulnerabilities catalog
- — CISA remediation deadline for US federal agencies
- — CVE record last updated
Sources and references
Original sources first. Version and fix details should always be confirmed against the vendor or project advisory.
Vendor and project advisories, patches
- Listed in CISA KEV notes (docs.libraesva.com) docs.libraesva.com
Vulnerability records
- CVE.org record CVE-2025-59689 cve.org
- NVD entry CVE-2025-59689 nvd.nist.gov
Government
Other references from the CVE record and advisory
- libraesva.com libraesva.com
All exploited Libraesva vulnerabilities · Today’s Security Digest