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CVE-2025-66511 Detail

Description

Nextcloud Calendar is a calendar app for Nextcloud. Prior to 6.0.3, the Calendar app generates participant tokens for meeting proposals using a hash function, allowing an attacker to compute valid participant tokens, which allowed them to request details and submit dates in meeting proposals. The tokens are not purely random generated. This vulnerability is fixed in 6.0.3.


Metrics

NVD enrichment efforts reference publicly available information to associate vector strings. CVSS information contributed by other sources is also displayed.
CVSS 4.0 Severity and Vector Strings:

NIST CVSS score
NIST: NVD
N/A
NVD assessment not yet provided.

References to Advisories, Solutions, and Tools

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URL Source(s) Tag(s)
https://github.com/nextcloud/calendar/commit/8de14ae87f321f5f09280d9895a27d54d24f33fb GitHub, Inc.
https://github.com/nextcloud/calendar/pull/7659 GitHub, Inc.
https://github.com/nextcloud/security-advisories/security/advisories/GHSA-whm3-vv55-gf27 GitHub, Inc.
https://hackerone.com/reports/3385434 GitHub, Inc.

Weakness Enumeration

CWE-ID CWE Name Source
CWE-330 Use of Insufficiently Random Values GitHub, Inc.  

Change History

1 change records found show changes

Quick Info

CVE Dictionary Entry:
CVE-2025-66511
NVD Published Date:
12/05/2025
NVD Last Modified:
12/05/2025
Source:
GitHub, Inc.