CVE-2026-107567: Use of Less Trusted Source

Use of a less trusted source in the DKIM signing of Progressive Robot hMailServer 6.0.0 through 6.3.6 allows a remote unauthenticated attacker to have mail they write signed with the DKIM key of a domain the server hosts, so that it passes DKIM and DMARC for that domain at other receivers. With...

CVE-2026-107571: Incorrect Default Permissions

Incorrect default permissions in the Windows installer of Progressive Robot hMailServer 6.0.0 through 6.3.6 allow a local authenticated user to run code as the mail server's high-privileged accounts when the product is installed in a folder whose permissions are inherited from a writable parent,...

PT-2026-117456

Name of the Vulnerable Software and Affected Versions Progressive Robot hMailServer versions 6.0.0 through 6.3.6 Description Unchecked input for a loop condition allows a remote unauthenticated attacker to cause a denial of service by stopping the mail server. The server uses the...

PT-2026-117455

Name of the Vulnerable Software and Affected Versions hMailServer versions 6.2.22 through 6.3.6 hMailServer versions 6.0.0 through 6.3.6 Description Missing authorization in the Sieve notify action and the mail-rule Reply action allows an authenticated user to send emails through the server using...

PT-2026-117454

Name of the Vulnerable Software and Affected Versions Progressive Robot hMailServer versions 6.0.0 through 6.3.6 Description An issue exists in the DKIM signing process where the server uses a less trusted source, allowing a remote unauthenticated attacker to have emails signed with the DKIM key ...

CVE-2026-107569: Unchecked Input for Loop Condition

Unchecked input for a loop condition in Progressive Robot hMailServer 6.0.0 through 6.3.6 allows a remote unauthenticated attacker to stop the server carrying mail. The server bounds the mail it generates in response to a message - a rule forward, reply or copy, an account forward, a Sieve...

PT-2026-117453

Name of the Vulnerable Software and Affected Versions Progressive Robot hMailServer versions 6.2.22 through 6.3.6 Progressive Robot hMailServer versions 6.0.0 through 6.3.6 Description Missing authorization in the Sieve editheader action and the mail-rule Set header value action allows an...

CVE-2026-107568: Missing Authorization

Missing authorization in the Sieve notify action 6.2.22 through 6.3.6 and in the mail-rule Reply action 6.0.0 through 6.3.6 of Progressive Robot hMailServer allows an authenticated user to send mail through the server as any address. A Sieve notify sends a notification message, and its :from tag...

PT-2026-117457

Name of the Vulnerable Software and Affected Versions Progressive Robot hMailServer versions 6.0.0 through 6.3.6 Description Incorrect default permissions in the Windows installer allow a local authenticated user to execute code with high-privileged accounts, such as LocalSystem or the service's...

CVE-2026-107566: Missing Authorization

Missing authorization in the Sieve editheader action 6.2.22 through 6.3.6 and in the mail-rule Set header value action 6.0.0 through 6.3.6 of Progressive Robot hMailServer allows an authenticated user to make the server send mail as any address, DKIM-signed where the address is at a domain the...

CVE-2026-107585

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-2026-107586

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. The table of browser sessions, shared by every account, the server administrator and support sessions, dropped...

CVE-2026-107586 Allocation of Resources Without Limits or Throttling in hMailServer

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. The table of browser sessions, shared by every account, the server administrator and support sessions, dropped...

CVE-2026-107586

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. The table of browser sessions, shared by every account, the server administrator and support sessions, dropped...

EUVD-2026-95038

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. The table of browser sessions, shared by every account, the server administrator and support sessions, dropped...

CVE-2026-107586 Allocation of Resources Without Limits or Throttling in hMailServer

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. The table of browser sessions, shared by every account, the server administrator and support sessions, dropped...

CVE-2026-107586

Progressive Robot hMailServer versions 6.2.28 through 6.3.5 are vulnerable to an uncontrolled eviction in the REST API's browser session table. Because the table is shared across all accounts and lacks a per-account session limit, a remote authenticated user can intentionally fill the table by re...

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-2026-107585 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...

CVE-2026-107585

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...