CVE-2026-107585 Allocation of Resources Without Limits or Throttling in hMailServer

Uncontrolled eviction in the pending sign-in tables of the REST API in Progressive Robot hMailServer 6.3.4 and 6.3.5 allows a remote unauthenticated attacker to make other users' OpenID Connect, SAML and passkey sign-ins fail. The routes that start a single sign-on and hand out a passkey sign-in...

EUVD-2026-95037

Uncontrolled eviction in the pending sign-in tables of the REST API in Progressive Robot hMailServer 6.3.4 and 6.3.5 allows a remote unauthenticated attacker to make other users' OpenID Connect, SAML and passkey sign-ins fail. The routes that start a single sign-on and hand out a passkey sign-in...

CVE-2026-107587

Improper certificate validation in the webmail of Progressive Robot hMailServer 6.3.2 through 6.3.5 allows a remote unauthenticated attacker to have S/MIME-encrypted mail that the account later sends to another correspondent also encrypted to the attacker's key. When its recipient opened a signed...

CVE-2026-107581

Progressive Robot hMailServer 6.0.0 through 6.3.5 processes several IMAP commands from a signed-in account in time quadratic in the command's length or in the number of elements it names, and can be made to hold memory out of proportion to a command. The FETCH data-item parser normalised a BODY...

CVE-2026-107582

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-2026-107583

Inefficient algorithmic complexity in the webmail's message view of the REST API in Progressive Robot hMailServer 6.3.2 through 6.3.5 allows a remote unauthenticated attacker to make the webmail, the administration console and the REST API unavailable by sending a message. The route that renders ...

CVE-2026-107584

Progressive Robot hMailServer 6.0.0 through 6.3.5 fails open when applying DANE RFC 7672 to outbound SMTP delivery. The server's validating DNSSEC resolver treated a TLSA or MX lookup that did not complete no answer, SERVFAIL, a malformed reply, an answer without the requested records and without...

CVE-2026-107580

Inefficient algorithmic complexity in the decoding of message header fields in Progressive Robot hMailServer 6.0.0 through 6.3.5 allows a remote unauthenticated attacker to make the IMAP, SMTP and POP3 services, or the webmail, unavailable by sending a message. The server unfolded a decoded heade...

CVE-2026-107573

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-2026-107575

Inefficient algorithmic complexity in the SPF macro expansion of Progressive Robot hMailServer 6.3.4 and 6.3.5 allows a remote unauthenticated attacker to consume worker-thread time by publishing a crafted SPF record. RFC 7208 section 7.1 requires a name too long to look up to lose whole labels...

CVE-2026-107576

Inefficient algorithmic complexity in the inbound DKIM and ARC signature verification of Progressive Robot hMailServer 6.0.0 through 6.3.5 allows a remote unauthenticated attacker to make the mail services unavailable by sending a message. Building the canonical header and choosing the header...

CVE-2026-107577

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-2026-107578

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-2026-107579

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-2026-107574

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-2026-107572

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-2026-107584 Not Failing Securely ('Failing Open') in hMailServer

Progressive Robot hMailServer 6.0.0 through 6.3.5 fails open when applying DANE RFC 7672 to outbound SMTP delivery. The server's validating DNSSEC resolver treated a TLSA or MX lookup that did not complete no answer, SERVFAIL, a malformed reply, an answer without the requested records and without...

CVE-2026-107584 Not Failing Securely ('Failing Open') in hMailServer

Progressive Robot hMailServer 6.0.0 through 6.3.5 fails open when applying DANE RFC 7672 to outbound SMTP delivery. The server's validating DNSSEC resolver treated a TLSA or MX lookup that did not complete no answer, SERVFAIL, a malformed reply, an answer without the requested records and without...

CVE-2026-107584

Progressive Robot hMailServer versions 6.0.0 through 6.3.5 are vulnerable to a fail-open condition when applying DANE (RFC 7672) to outbound SMTP delivery. The root cause is that the server's validating DNSSEC resolver treats incomplete lookups (no answer, SERVFAIL, or malformed replies), records...

EUVD-2026-94867

Progressive Robot hMailServer 6.0.0 through 6.3.5 fails open when applying DANE RFC 7672 to outbound SMTP delivery. The server's validating DNSSEC resolver treated a TLSA or MX lookup that did not complete no answer, SERVFAIL, a malformed reply, an answer without the requested records and without...