🛡️ CVE-2025-66556 — talk

🟢 CVSS 3.5 — Low ✅ No Known Exploit CWE-639 NVD
3.5
CVSS Score
0 Low4 Medium7 High9 Critical10

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.

How this vulnerability can be exploited

This issue can be reached over the network, attack complexity is low, an attacker needs low-level privileges on the target. A user must be tricked into taking some action. The scope is unchanged, so the impact stays within the vulnerable component. Rated impact: confidentiality none, integrity low, availability none.

Weakness class

CVE-2025-66556 is classified as CWE-639: Authorization Bypass Through User-Controlled Key. An object is selected by an identifier from the request without checking the caller owns it.

Affected software

CVE-2025-66556 is recorded against 1 package.

  • talk (from 21.0.0 up to 21.1.2)

Timeline and source

Published on 5 December 2025 and last revised on 17 June 2026. No public exploit is currently recorded for this entry. A vendor advisory or fix has been published. Record sourced from NVD.

References

github.com
github.com
github.com
hackerone.com

Details

Severity LOW
CVSS Score 3.5
CVSS Vector CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:L/A:N
CWE CWE-639
Public Exploit ✅ No
Source NVD
Published 2025-12-05
Updated 2026-08-11
Modified 2026-06-17

Affected Packages

Software From version Fixed in
talk 21.0.0 21.1.2

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