A vulnerability relating to insufficient access control has been identified in the session management of the Sesame Time web application and its REST v3 API. The flaw lies in the fact that the system uses the session identifier (USID) as the sole validation mechanism, without verifying whether that identifier legitimately belongs to the user making the request. As a result, an attacker who obtains a valid USID can impersonate a victim’s session and access their confidential information, including emails, user IDs, roles and corporate data. This vulnerability is exacerbated by poor session lifecycle management: new logins generate additional USIDs without revoking the previous ones, allowing multiple active sessions to coexist and thereby expanding the attack surface.
History

Tue, 14 Jul 2026 12:15:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Tue, 14 Jul 2026 10:30:00 +0000

Type Values Removed Values Added
Description A vulnerability relating to insufficient access control has been identified in the session management of the Sesame Time web application and its REST v3 API. The flaw lies in the fact that the system uses the session identifier (USID) as the sole validation mechanism, without verifying whether that identifier legitimately belongs to the user making the request. As a result, an attacker who obtains a valid USID can impersonate a victim’s session and access their confidential information, including emails, user IDs, roles and corporate data. This vulnerability is exacerbated by poor session lifecycle management: new logins generate additional USIDs without revoking the previous ones, allowing multiple active sessions to coexist and thereby expanding the attack surface.
Title Inadequate access control in Sesame Time session management
Weaknesses CWE-639
References
Metrics cvssV4_0

{'score': 8.7, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N'}


cve-icon MITRE

Status: PUBLISHED

Assigner: INCIBE

Published:

Updated: 2026-07-14T12:08:21.909Z

Reserved: 2026-07-10T11:40:35.281Z

Link: CVE-2026-15389

cve-icon Vulnrichment

Updated: 2026-07-14T12:08:12.541Z

cve-icon NVD

No data.

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.