SB2025120536 - Authorization bypass through user-controlled key in Nextcloud Talk
Published: December 5, 2025
Security Bulletin ID
SB2025120536
CSH Severity
Medium
Patch available
YES
Number of vulnerabilities
1
Exploitation vector
Remote access
Highest impact
Data manipulation
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 1 vulnerability.
1) Authorization bypass through user-controlled key (CVE-ID: CVE-2025-66556)
CWE-ID: CWE-639 - Authorization Bypass Through User-Controlled Key
CVSSv4: 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
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.
Remediation
Install update from vendor's website.