CVE-2026-104084

SmarterMail before build 9777 contains a privilege escalation vulnerability where JWT access and refresh tokens embed a role claim at issuance that is not revalidated against the account's current role when redeemed through POST /api/v1/auth/refresh-token. Attackers who capture a refresh token issued before an administrator demotion, or a demoted user whose session was not actively polling at the time of demotion, can replay the stale token to obtain a new access token retaining the higher-privilege role (such as DomainAdmin or SysAdmin) until natural token expiry.

CVSS v3 8.8 HIGH

8.8^/10

CVSS v3 : HIGH

Vector :

Exploitability : 2.8 / Impact : 5.9

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required LOW

User Interaction NONE

Confidentiality Impact HIGH

Integrity Impact HIGH

Availability Impact HIGH

Scope UNCHANGED

References

Link	Resource
https://blog.evan.lat/posts/sm/
https://www.smartertools.com/smartermail/release-notes/current#/9526:~:text=Build%209777%20(Oct%208%2C%202026)
https://www.vulncheck.com/advisories/smartermail-build-9777-stale-jwt-role-claim-privilege-escalation-via-refresh-token

Configurations

No configuration.

History

12 Oct 2026, 14:17

Type	Values Removed	Values Added
References		() https://blog.evan.lat/posts/sm/ -

09 Oct 2026, 16:17

Type	Values Removed	Values Added
New CVE

Information

Published : 2026-10-09 16:17

Updated : 2026-10-12 14:17

NVD link : CVE-2026-104084

Mitre link : CVE-2026-104084

CVE.ORG link : CVE-2026-104084

JSON object : View

Products Affected

No product.

CWE

CWE-613

Insufficient Session Expiration

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