CVE-2026-103010

Heap-based buffer overflow in the legacy Blowfish decryption routine (BlowFishEncryptor::DecryptFromString) in Progressive Robot hMailServer 6.0.0 through 6.3.3 on Windows allows a local interactive user with no hMailServer credentials to write bytes of their choosing past the end of a 255-byte heap buffer in the hMailServer service process, which runs as LocalSystem by default. The user does this by passing a long hexadecimal string to the COM method Utilities.BlowfishDecrypt, which checked no authentication. The routine converted hexadecimal input of any length into a fixed 255-byte buffer before decrypting it in place. The result is a denial of service (service crash), and possibly code execution with the privileges of the service account.

CVSS v3 7.8 HIGH

7.8^/10

CVSS v3 : HIGH

Vector :

Exploitability : 1.8 / Impact : 5.9

Attack Vector LOCAL

Attack Complexity LOW

Privileges Required LOW

User Interaction NONE

Confidentiality Impact HIGH

Integrity Impact HIGH

Availability Impact HIGH

Scope UNCHANGED

References

Link	Resource
https://gitlab.com/hmailserver/hmailserver/-/commit/135a1908ff820ed587d5f180f98c53bd010d8931
https://gitlab.com/hmailserver/hmailserver/-/releases/v6.3.4
https://gitlab.com/hmailserver/hmailserver/-/work_items/49

Configurations

No configuration.

History

08 Oct 2026, 11:16

Type	Values Removed	Values Added
New CVE

Information

Published : 2026-10-08 11:16

Updated : 2026-10-08 21:02

NVD link : CVE-2026-103010

Mitre link : CVE-2026-103010

CVE.ORG link : CVE-2026-103010

JSON object : View

Products Affected

No product.

CWE

CWE-122

Heap-based Buffer Overflow

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