Spacebar Server before commit dcfd910 contains a missing authorization vulnerability that allows any authenticated attacker to add themselves to arbitrary group DM channels by sending a PUT request to the channels recipient endpoint without membership verification. Attackers can exploit the unguarded PUT /channels/{channel_id}/recipients/{user_id} handler to join private group DMs, read complete message history, post messages as a participant, and force-add third-party users without their consent.

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History

Fri, 07 Aug 2026 10:30:00 +0000

Type Values Removed Values Added
First Time appeared Spacebar Server
Spacebar Server spacebar Server
Vendors & Products Spacebar Server
Spacebar Server spacebar Server

Thu, 06 Aug 2026 18:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'poc', 'Technical Impact': 'total'}, 'version': '2.0.3'}


Wed, 05 Aug 2026 20:15:00 +0000

Type Values Removed Values Added
Description Spacebar Server before commit dcfd910 contains a missing authorization vulnerability that allows any authenticated attacker to add themselves to arbitrary group DM channels by sending a PUT request to the channels recipient endpoint without membership verification. Attackers can exploit the unguarded PUT /channels/{channel_id}/recipients/{user_id} handler to join private group DMs, read complete message history, post messages as a participant, and force-add third-party users without their consent.
Title Spacebar Server Missing Authorization via Group DM Recipient Endpoint
Weaknesses CWE-862
References
Metrics cvssV3_1

{'score': 8.1, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N'}

cvssV4_0

{'score': 8.6, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N'}


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cve-icon MITRE

Status: PUBLISHED

Assigner: VulnCheck

Published:

Updated: 2026-08-06T18:07:53.147Z

Reserved: 2026-08-04T20:17:18.296Z

Link: CVE-2026-70617

cve-icon Vulnrichment

Updated: 2026-08-06T17:54:36.211Z

cve-icon NVD

Status : Deferred

Published: 2026-08-05T20:17:17.770

Modified: 2026-09-16T20:34:51.637

Link: CVE-2026-70617

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-08-07T10:05:07Z

Weaknesses