EUVD-2026-94864

Inefficient algorithmic complexity in the REST API 6.3.3 through 6.3.5 and the IMAP PREVIEW response 6.2.22 through 6.3.5 of Progressive Robot hMailServer allows a remote unauthenticated attacker to make the webmail, the administration console and the REST API unavailable by sending a message. To...

CVE-2026-107580

Progressive Robot hMailServer versions 6.0.0 through 6.3.5 are vulnerable to a Denial of Service (DoS) attack due to inefficient algorithmic complexity during the decoding of message header fields. A remote unauthenticated attacker can send a message containing an RFC 2047 encoded word with a hig...

EUVD-2026-94861

Inefficient algorithmic complexity in the bounce and complaint processing of Progressive Robot hMailServer 6.3.4 and 6.3.5 allows a remote unauthenticated attacker to stop mail delivery by sending messages, when bounce processing or complaint processing is enabled or a mailing list is managed by...

CVE-2026-107579 Inefficient Algorithmic Complexity in hMailServer

Inefficient algorithmic complexity in the bounce and complaint processing of Progressive Robot hMailServer 6.3.4 and 6.3.5 allows a remote unauthenticated attacker to stop mail delivery by sending messages, when bounce processing or complaint processing is enabled or a mailing list is managed by...

CVE-2026-107579 Inefficient Algorithmic Complexity in hMailServer

Inefficient algorithmic complexity in the bounce and complaint processing of Progressive Robot hMailServer 6.3.4 and 6.3.5 allows a remote unauthenticated attacker to stop mail delivery by sending messages, when bounce processing or complaint processing is enabled or a mailing list is managed by...

EUVD-2026-94860

Improper link resolution and external control of file paths in the administrative command-line operations of hMailServer.exe in Progressive Robot hMailServer 6.3.4 and 6.3.5 allow a local attacker who already runs code as the low-privilege service account to escalate privilege. On Windows,...

CVE-2026-107577 Loop with Unreachable Exit Condition ('Infinite Loop') in hMailServer

Inefficient algorithmic complexity and a non-terminating loop in the MIME processing of received messages in Progressive Robot hMailServer 6.0.0 through 6.3.5 allow a remote unauthenticated attacker to make the mail services unavailable by sending a message. Removing a MIME header parameter whose...

EUVD-2026-94858

Inefficient algorithmic complexity and a non-terminating loop in the MIME processing of received messages in Progressive Robot hMailServer 6.0.0 through 6.3.5 allow a remote unauthenticated attacker to make the mail services unavailable by sending a message. Removing a MIME header parameter whose...

CVE-2026-107572

Progressive Robot hMailServer versions 6.2.24 through 6.3.5 are vulnerable to a Denial of Service (DoS) condition due to inefficient complexity in Sieve filter evaluation. The vulnerability arises from a backtracking descent during :matches pattern matching, where execution time grows exponential...

EUVD-2026-94856

Inefficient complexity in the Sieve filter evaluation of Progressive Robot hMailServer 6.2.24 through 6.3.5 allows an authenticated account holder to make the mail services unavailable with their own filter. A ':matches' pattern was matched by a backtracking descent whose time grew with the match...

CVE-2026-107573 Incorrect Default Permissions in hMailServer

Incorrect default permissions in the Windows installer of Progressive Robot hMailServer 6.0.0 through 6.3.5 allow a local authenticated user to read the mail server's data. The installer created the data, log, temp, database and event folders and the hMailServer.INI configuration file with the...

CVE-2026-107573

Progressive Robot hMailServer versions 6.0.0 through 6.3.5 on Windows suffer from incorrect default permissions in the installer. The installer creates data, log, temp, database, and event folders, along with the hMailServer.INI configuration file, using permissions inherited from the installatio...

CVE-2026-107573 Incorrect Default Permissions in hMailServer

Incorrect default permissions in the Windows installer of Progressive Robot hMailServer 6.0.0 through 6.3.5 allow a local authenticated user to read the mail server's data. The installer created the data, log, temp, database and event folders and the hMailServer.INI configuration file with the...

EUVD-2026-94854

Inefficient algorithmic complexity in the JSON reader of Progressive Robot hMailServer allows a remote unauthenticated attacker to make the mail services unavailable. Reading a JSON object kept the first of each duplicated member name by searching the members already read, so an object of N...

CVE-2026-107574

Progressive Robot hMailServer is vulnerable to a Denial of Service (DoS) attack due to inefficient algorithmic complexity (O(N^2)) in its JSON reader. The component fails to efficiently handle duplicated member names, causing significant processing delays: a 4 MB object can take 300 seconds to pr...

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-2026-104658

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-2026-103647

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...