CVE-2026-104658

The Linux live-update apply helper hmailserver-update of Progressive Robot hMailServer 6.3.4 and 6.3.5 runs as root on a request file written by the unprivileged hmailserver service account, and took from that request the program used to verify an AppImage update's signature and the systemd unit ...

CVE-2026-103649

Missing network timeouts in the Linux builds of Progressive Robot hMailServer 6.3.0 through 6.3.5 allow a remote attacker to hold server threads indefinitely and so stop outbound mail delivery denial of service. The server set its socket timeouts in the form Windows takes, which Linux refuses, an...

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 hea...

CVE-2026-103647

Cross-site scripting in the webmail of Progressive Robot hMailServer 6.3.2 through 6.3.5 allows a remote attacker who can send a user an encrypted message to run script in the webmail's origin with that user's session. When the webmail decrypted an S/MIME message from 6.3.2 or an OpenPGP message...

CVE-2026-103011

Heap-based buffer overflow in the legacy Blowfish encryption routine BlowFishEncryptor::Encode, called by EncryptToString in Progressive Robot hMailServer 6.0.0 through 6.3.5 allows an authenticated mailbox user to cause a denial of service service crash, and possibly other unspecified impact. In...

CVE-2026-103011

Progressive Robot hMailServer versions 6.0.0 through 6.3.5 are vulnerable to a heap-based buffer overflow in the legacy Blowfish encryption routine (BlowFishEncryptor::Encode , called by EncryptToString ). The flaw occurs because the padding loop can write up to 7 zero bytes between 2 and 232 byt...

CVE-2026-103011 Heap-based Buffer Overflow in hMailServer

Heap-based buffer overflow in the legacy Blowfish encryption routine BlowFishEncryptor::Encode, called by EncryptToString in Progressive Robot hMailServer 6.0.0 through 6.3.5 allows an authenticated mailbox user to cause a denial of service service crash, and possibly other unspecified impact. In...

EUVD-2026-94838

Heap-based buffer overflow in the legacy Blowfish encryption routine BlowFishEncryptor::Encode, called by EncryptToString in Progressive Robot hMailServer 6.0.0 through 6.3.5 allows an authenticated mailbox user to cause a denial of service service crash, and possibly other unspecified impact. In...

CVE-2026-103011 Heap-based Buffer Overflow in hMailServer

Heap-based buffer overflow in the legacy Blowfish encryption routine BlowFishEncryptor::Encode, called by EncryptToString in Progressive Robot hMailServer 6.0.0 through 6.3.5 allows an authenticated mailbox user to cause a denial of service service crash, and possibly other unspecified impact. In...

EUVD-2026-94837

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 hea...

CVE-2026-103010

Progressive Robot hMailServer versions 6.0.0 through 6.3.3 on Windows are vulnerable to a heap-based buffer overflow in the legacy Blowfish decryption routine (BlowFishEncryptor::DecryptFromString ). A local interactive user without credentials can exploit this by passing a long hexadecimal strin...

CVE-2026-103010 Heap-based Buffer Overflow in hMailServer

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 hea...

CVE-2026-103010 Heap-based Buffer Overflow in hMailServer

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 hea...

CVE-2026-103647 Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') in hMailServer

Cross-site scripting in the webmail of Progressive Robot hMailServer 6.3.2 through 6.3.5 allows a remote attacker who can send a user an encrypted message to run script in the webmail's origin with that user's session. When the webmail decrypted an S/MIME message from 6.3.2 or an OpenPGP message...

CVE-2026-103647 Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') in hMailServer

Cross-site scripting in the webmail of Progressive Robot hMailServer 6.3.2 through 6.3.5 allows a remote attacker who can send a user an encrypted message to run script in the webmail's origin with that user's session. When the webmail decrypted an S/MIME message from 6.3.2 or an OpenPGP message...

CVE-2026-103647

Progressive Robot hMailServer versions 6.3.2 through 6.3.5 are vulnerable to Cross-Site Scripting (XSS) in the webmail component. The root cause occurs when the webmail decrypts S/MIME (version 6.3.2) or OpenPGP (version 6.3.4) messages in a browser, offering decrypted attachments as blob URLs ba...

CVE-2026-103647

Cross-site scripting in the webmail of Progressive Robot hMailServer 6.3.2 through 6.3.5 allows a remote attacker who can send a user an encrypted message to run script in the webmail's origin with that user's session. When the webmail decrypted an S/MIME message from 6.3.2 or an OpenPGP message...

CVE-2026-103647 Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') in hMailServer

Cross-site scripting in the webmail of Progressive Robot hMailServer 6.3.2 through 6.3.5 allows a remote attacker who can send a user an encrypted message to run script in the webmail's origin with that user's session. When the webmail decrypted an S/MIME message from 6.3.2 or an OpenPGP message...

EUVD-2026-94836

Cross-site scripting in the webmail of Progressive Robot hMailServer 6.3.2 through 6.3.5 allows a remote attacker who can send a user an encrypted message to run script in the webmail's origin with that user's session. When the webmail decrypted an S/MIME message from 6.3.2 or an OpenPGP message...

CVE-2026-103649

Linux builds of Progressive Robot hMailServer versions 6.3.0 through 6.3.5 are vulnerable to a denial of service (DoS) due to missing network timeouts. The root cause is that the server sets socket timeouts in a Windows-specific format which Linux rejects, causing HTTPS clients to read without a ...