Priority LOW 20
Uncontrolled eviction in the browser session table of the REST API in Progressive Robot hMailServer 6.2.28 through 6.3.5 allows a remote authenticated user to end other users' sessions.
CVSS 3.1MEDIUM 4.3· Network · Low privileges · No interaction · EPSS 0.00338 · Published 2026-10-08 · Fixed in 6.3.6 CWE-770
Priority LOW 30
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…
CVSS 3.1MEDIUM 5.3· Network · No auth · No interaction · EPSS 0.00448 · Published 2026-10-08 · Fixed in 6.3.6 CWE-770
Priority LOW 33
Progressive Robot hMailServer 6.0.0 through 6.3.5 fails open when applying DANE (RFC 7672) to outbound SMTP delivery.
CVSS 3.1HIGH 7.4· Network · No auth · No interaction · EPSS 0.00151 · Published 2026-10-08 · Fixed in 6.3.6 CWE-636
Priority LOW 28
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 conso…
CVSS 3.1MEDIUM 6.5· Network · No auth · User interaction · EPSS 0.00257 · Published 2026-10-08 · Fixed in 6.3.6 CWE-407
Priority LOW 26
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 correspon…
CVSS 3.1MEDIUM 5.9· Network · No auth · User interaction · EPSS 0.00169 · Published 2026-10-08 · Fixed in 6.3.6 CWE-295
Priority LOW 28
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,…
CVSS 3.1MEDIUM 6.5· Network · No auth · User interaction · EPSS 0.00257 · Published 2026-10-08 · Fixed in 6.3.6 CWE-407
Priority LOW 28
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 o…
CVSS 3.1MEDIUM 6.5· Network · Low privileges · No interaction · EPSS 0.00249 · Published 2026-10-08 · Fixed in 6.3.6 CWE-407
Priority LOW 28
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 w…
CVSS 3.1MEDIUM 6.5· Network · No auth · User interaction · EPSS 0.00257 · Published 2026-10-08 · Fixed in 6.3.6 CWE-407
Priority LOW 39
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 p…
CVSS 3.1HIGH 7.5· Network · No auth · No interaction · EPSS 0.00347 · Published 2026-10-08 · Fixed in 6.3.6 CWE-407
Priority LOW 30
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 a…
CVSS 3.1MEDIUM 6.7· Local · Low privileges · User interaction · EPSS 0.00073 · Published 2026-10-08 · Fixed in 6.3.6 CWE-59
Priority LOW 39
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…
CVSS 3.1HIGH 7.5· Network · No auth · No interaction · EPSS 0.00428 · Published 2026-10-08 · Fixed in 6.3.6 CWE-407
Priority LOW 39
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 serv…
CVSS 3.1HIGH 7.5· Network · No auth · No interaction · EPSS 0.00428 · Published 2026-10-08 · Fixed in 6.3.6 CWE-835
Priority LOW 30
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.
CVSS 3.1MEDIUM 5.3· Network · No auth · No interaction · EPSS 0.00387 · Published 2026-10-08 · Fixed in 6.3.6 CWE-407
Priority LOW 29
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.
CVSS 3.1MEDIUM 6.5· Network · Low privileges · No interaction · EPSS 0.00307 · Published 2026-10-08 · Fixed in 6.3.6 CWE-1333
Priority LOW 35
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.
CVSS 3.1HIGH 7.8· Local · Low privileges · No interaction · EPSS 0.00102 · Published 2026-10-08 · Fixed in 6.3.6 CWE-276
Priority LOW 39
Inefficient algorithmic complexity in the JSON reader of Progressive Robot hMailServer allows a remote unauthenticated attacker to make the mail services unavailable.
CVSS 3.1HIGH 7.5· Network · No auth · No interaction · EPSS 0.00428 · Published 2026-10-08 · Fixed in 6.3.6 CWE-407
Priority LOW 28
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 cau…
CVSS 3.1MEDIUM 6.5· Network · Low privileges · No interaction · EPSS 0.00211 · Published 2026-10-08 · Fixed in 6.3.6 CWE-122
Priority LOW 36
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.
CVSS 3.1HIGH 8.0· Network · No auth · User interaction · EPSS 0.00247 · Published 2026-10-08 · Fixed in 6.3.6 CWE-79
Priority LOW 38
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).
CVSS 3.1HIGH 7.5· Network · No auth · No interaction · EPSS 0.0027 · Published 2026-10-08 · Fixed in 6.3.6 CWE-1088
Priority LOW 34
Missing Host header validation and missing throttling of failed administrator sign-ins in the REST API listener of Progressive Robot hMailServer 6.0.0 through 6.3.5 allow a remote attacker to brute-force the server admin…
CVSS 3.1HIGH 7.5· Network · No auth · User interaction · EPSS 0.00143 · Published 2026-10-08 · Fixed in 6.3.6 CWE-346
Priority LOW 35
Missing authorization on COM objects in Progressive Robot hMailServer 6.0.0 through 6.3.5 (Windows only) lets a local interactive user with no hMailServer credential read and write arbitrary files as the service account…
CVSS 3.1HIGH 7.8· Local · Low privileges · No interaction · EPSS 0.00107 · Published 2026-10-08 · Fixed in 6.3.6 CWE-862
Priority LOW 35
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…
CVSS 3.1HIGH 7.8· Local · Low privileges · No interaction · EPSS 0.00114 · Published 2026-10-08 · Fixed in 6.3.6 CWE-807
Priority LOW 33
Progressive Robot hMailServer 6.0.0 through 6.3.5 does not enforce TLS for outbound SMTP delivery to a mail exchanger whose DNSSEC-validated TLSA records contain no DANE-EE (usage 3) record, contrary to RFC 7672 section…
CVSS 3.1HIGH 7.4· Network · No auth · No interaction · EPSS 0.0015 · Published 2026-10-08 · Fixed in 6.3.6 CWE-319