VULNERABILITY INTELLIGENCE
CVE-2026-70617
CVSS score8.1 HIGH
EPSS probability0.41%
CISA KEVNot currently listed
Published2026-08-05
Last modified2026-09-16
CVSS vectorCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N
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.
Weakness classification
- disclosure@vulncheck.com: CWE-862