CVE-2025-34491 json
GFI MailEssentials < 21.8 MultiNode Insecure Deserialization
published 2025-04-28 18 mo ago modified 2026-06-17 4 mo ago also EUVD-2025-14683
- cvss
- 8.8
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 1.0%
- EPSS 1.0% chance of exploitation in 30 days, percentile 61%
- public exploits
- 0
- none known
Summary
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.
Patch / fix
- GFI MailEssentials 21.8
CISA SSVC
- Exploitation
- Proof of concept is public
- Automatable
- no
- Technical impact
- total
- Assessed
- 18 mo ago
Exploit prediction
0.96% chance of exploitation in the next 30 days, higher than 61% of all scored CVEs (FIRST EPSS, 2026-11-08).
Exploits and checks
- frycos.github.io https://frycos.github.io/vulns4free/2025/04/28/mailessentials.html referenced PoC, tagged "exploit" by a source, unverified
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.1 | 8.8 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H |
| NVD | 3.1 | 8.8 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H |
Affected products
- GFI MailEssentials
Classification
- Weakness
-
- CWE-502 Deserialization of Untrusted Data
References
-
frycos.github.io
/vulns4free/2025/04/28/mailessentials.html
technical-description, exploit
-
gfi.ai
/products-and-solutions/network-security-solutions/mailessentials/resources/documentation/product-releases
vendor-advisory, release-notes
-
vulncheck.com
/advisories/gfi-mailessentials-multinode-insecure-deserialization
third-party-advisory
Sources
- CVE List CVE-2025-34491
- NVD CVE-2025-34491
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