Grandstream BudgeTone (BT) 100 Voice over IP (VoIP) phones do not properly check the Call-ID, branch, and tag values in a NOTIFY message to verify a subscription, which allows remote attackers to spoof messages such as the "Messages waiting" message.
Severity
CVSS 3.1
7.5 high
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
EPSS
1.2% chance of exploitation in the next 30 days; higher than 67% of CVEs (scores of 2026-10-31)