Vulnerability Report

CVE-2025-66556

Title: Nextcloud Talk Poll Draft Deletion

Auth Bypass

Proof Of Concept

No public PoC currently indexed for CVE-2025-66556.

CWE Category CWE-639
Published Date Dec 05, 2025
Modified Date Oct 15, 2026
Exploit Status Not Found
Score 3.5 CVSS v3.1
Exploit Probability (EPSS)
0.25%

Vulnerability Summary

CVE-2025-66556: Nextcloud talk is a video & audio conferencing app for Nextcloud. Prior to 20.1.8 and 21.1.2, a participant with chat permissions was able to delete poll drafts of other participants within the conversation based on their numeric ID. This vulnerability is fixed in 20.1.8 and 21.1.2.

Impacted Vendors

D
drupal 1
N
nextcloud 1
G
google 1

Reference Links

https://github.com/nextcloud/security-advisories/security/advisories/GHSA-pr9f-vqgg-m2jh https://github.com/nextcloud/spreed/commit/bd68e80d1dea98d84c1d621c2c681238cf041725 https://github.com/nextcloud/spreed/pull/15532 https://hackerone.com/reports/3247386
CVSS v3.1
Source Entity [email protected]
Severity LOW
3.5
Attack Vector
NETWORK
Complexity
LOW
Privileges
N/A
Interaction
REQUIRED
Confidentiality
N/A
Integrity
N/A
Availability
N/A
Scope
UNCHANGED
RAW VECTOR CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:L/A:N
CVSS v3.1
Source Entity [email protected]
Severity MEDIUM
4.3
Attack Vector
NETWORK
Complexity
LOW
Privileges
N/A
Interaction
NONE
Confidentiality
N/A
Integrity
N/A
Availability
N/A
Scope
UNCHANGED
RAW VECTOR CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N

Associated Attack Patterns (CAPEC)

Total: Patterns

CVE-2025-66556 Exploits & PoCs (Proof Of Concept)

No public PoCs found in our database for this CVE.

MODIFIED

Vulnerability data updated via NVD.

MODIFIED

Vulnerability data or affected products updated.

MODIFIED

Vulnerability data updated via NVD.

PUBLISHED

Vulnerability first announced in NVD.

Attack Vector Matrix

Access Vector NETWORK
Complexity LOW
Privileges N/A
Interaction REQUIRED
CVSS Vector String CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:L/A:N

Affected Stack

No specific products linked.