How severe is CVE-2025-34491?

CVE-2025-34491 has a CVSS 3.x base score of 8.8, rated high severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2025-34491 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (50th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2025-34491?

CVE-2025-34491 affects Gfi Mailessentials. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2025-34491?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

Does CVE-2025-34491 have an EU (EUVD) identifier?

Yes. CVE-2025-34491 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-14683.

When was CVE-2025-34491 published?

CVE-2025-34491 was published on 2025-04-28 and last updated on 2026-06-17.

CVE-2025-34491

CVE-2025-34491 is a high-severity vulnerability in Gfi Mailessentials with a CVSS 3.x base score of 8.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-502.

Key facts

Severity: High (CVSS 3.x base score 8.8)
EPSS exploit prediction: 1% (50th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2025-14683
Weakness: CWE-502
Affected product: Gfi Mailessentials
Published: 2025-04-28
Last modified: 2026-06-17

Description

GFI MailEssentials prior to version 21.8 is vulnerable to a .NET deserialization issue. A remote and authenticated attacker can execute arbitrary code by sending crafted serialized .NET when joining to a Multi-Server setup.

Frequently asked questions

What is CVE-2025-34491?: GFI MailEssentials prior to version 21.8 is vulnerable to a .NET deserialization issue. A remote and authenticated attacker can execute arbitrary code by sending crafted serialized .NET when joining to a Multi-Server setup.
How severe is CVE-2025-34491?: CVE-2025-34491 has a CVSS 3.x base score of 8.8, rated high severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2025-34491 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (50th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2025-34491?: CVE-2025-34491 affects Gfi Mailessentials. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2025-34491?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
Does CVE-2025-34491 have an EU (EUVD) identifier?: Yes. CVE-2025-34491 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-14683.
When was CVE-2025-34491 published?: CVE-2025-34491 was published on 2025-04-28 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:gfi:mailessentials:*:*:*:*:*:*:*:*

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