Authorization bypass through user-controlled key in Talk - CVE-2025-66556
Published: December 5, 2025
Vulnerability identifier: #VU119223
CSH Severity: Medium
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:A/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:U/U:Green
CVE-ID: CVE-2025-66556
CWE-ID: CWE-639
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: Nextcloud
Affected software:
Talk
Talk
Detailed vulnerability description
The vulnerability allows a remote attacker to compromise the target system.
The vulnerability exists due to authorization bypass through user-controlled key. A remote user can delete poll drafts of other participants within the conversation based on their numeric ID.
How to mitigate CVE-2025-66556
Install updates from vendor's website.