CVE-2021-32689Network attack vector

Chat disclosure via reusable deleted-user identifiers

Published Jul 12, 2021 · Updated Aug 3, 2024

Incorrect ownership assignment in Nextcloud Talk before 11.2.2 allows remote authenticated users to read a prior user's chat messages. Deleted-user handling leaves one-to-one rooms associated with the reusable user identifier instead of changing their type and name to prevent rejoining. Exploitation requires a user provider that permits reuse of a deleted username; successful reuse exposes the earlier account's chat history.

CVSS severity8.1
High
EPSS probability1.00%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Incorrect ownership assignment in Nextcloud Talk before 11.2.2 allows remote authenticated users to read a prior user's chat messages. Deleted-user handling leaves one-to-one rooms associated with the reusable user identifier instead of changing their type and name to prevent rejoining. Exploitation requires a user provider that permits reuse of a deleted username; successful reuse exposes the earlier account's chat history.

The record

CVE
CVE-2021-32689
Published
Jul 12, 2021
Updated
Aug 3, 2024
Vendor
Nextcloud GmbH
Product
Nextcloud Security Advisories
Classifications
CWE-708, CWE-200, T1213.005
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Jul 12, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 3, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 11.2.2

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Nextcloud GmbH · Nextcloud Security Advisoriesversion=< 11.2.2

Published CVSS scores

4.0NIST NVDAV:N/AC:L/Au:S/C:P/I:N/A:N
8.1GitHub, Inc.CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N
6.5NIST NVDCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-708Incorrect Ownership Assignment
CWE-200Exposure of Sensitive Information to an Unauthorized Actor
T1213.005Messaging Applications

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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