CVE-2025-34491

HIGHNVD 8.88.8—Trending — 3 sources updated this weekElevated

8.8

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.

CVSS v3: 8.8
EG Score: 8.8(medium)
EPSS: 78.9%
KEV: Not listed

Published

April 28, 2025

Last Modified

November 4, 2025

References (3)

disclosure@vulncheckhttps://frycos.github.io/vulns4free/2025/04/28/mailessentials.html
disclosure@vulncheckhttps://gfi.ai/products-and-solutions/network-security-solutions/mailessentials/resources/documentation/product-releases
disclosure@vulncheckhttps://www.vulncheck.com/advisories/gfi-mailessentials-multinode-insecure-deserialization

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

CWE-502Deserialization of Untrusted Data

Data Freshness Timeline

(refreshed 14× in last 7d / 15× in last 30d)

Every time one of our enrichment pipelines (NVD, MITRE cvelistV5, EPSS, CISA KEV, GHSA, OSV, vendor advisories) ran against this CVE. Most recent first.

2026-06-05 22:46 UTCepss_batch
2026-06-05 22:46 UTCepss_batch
2026-06-05 06:10 UTCepss_batch
2026-06-05 06:10 UTCepss_batch
2026-06-04 13:12 UTCepss_batch
2026-06-04 13:12 UTCepss_batch
2026-06-02 20:12 UTCepss_batch
2026-06-01 13:51 UTCepss_batch
2026-06-01 13:51 UTCepss_batch
2026-05-31 22:30 UTCepss_batch
2026-05-31 22:30 UTCepss_batch
2026-05-31 00:16 UTCepss_batch
2026-05-30 06:47 UTCEG score recompute
2026-05-30 06:46 UTCGHSA enrichment
2026-05-29 13:44 UTCepss_batch

Frequently asked(5)

What is CVE-2025-34491?

CVE-2025-34491 is a high vulnerability published on April 28, 2025. 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.

When was CVE-2025-34491 disclosed?

CVE-2025-34491 was first published in the National Vulnerability Database on April 28, 2025, with the most recent update on November 4, 2025. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.

Is CVE-2025-34491 actively exploited?

CVE-2025-34491 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 78.9% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.

What is the CVSS score of CVE-2025-34491?

CVE-2025-34491 has a CVSS v3 base score of 8.8 (NVD).

How do I remediate CVE-2025-34491?

Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2025-34491, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

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CVE-2025-34491

📅 Published

🔄 Last Modified

🔗 References (3)

Weakness Classification(1)

Data Freshness Timeline

❓ Frequently asked(5)

Dependency Blast Radius

Is Your Infrastructure Affected by CVE-2025-34491?

🔗 Related CVEs(same CWE)

Same CWE

Published

Last Modified

References (3)

Frequently asked(5)

Related CVEs(same CWE)