Medium severity · published Dec 5, 2025
CVE-2025-66556
Nextcloud talk allows participants to blindly delete poll drafts of other users by ID
4.3
CVSS
0.3%
EPSS
No
On KEV
Description
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.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
None
Confidentiality
None
Integrity
Low
Availability
None
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.3% · higher than 17% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
SE
security-advisories · nextcloud
< 20.1.8; >= 21.0.0-beta.1, < 21.1.2 · source: vendor
TA
Talk · Nextcloud
20.0.0 before 20.1.8; 21.0.0 before 21.1.2 · source: NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2025-66556
CVE.org
https://www.cve.org/CVERecord?id=CVE-2025-66556
Patch
https://github.com/nextcloud/security-advisories/security/advisories/GHSA-pr9f-vqgg-m2jh
Patch
https://github.com/nextcloud/spreed/commit/bd68e80d1dea98d84c1d621c2c681238cf041725
Issue Tracking
https://github.com/nextcloud/spreed/pull/15532
Issue Tracking
https://hackerone.com/reports/3247386
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