CVE-2025-66511

Source
https://cve.org/CVERecord?id=CVE-2025-66511
Import Source
https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2025-66511.json
JSON Data
https://api.osv.dev/v1/vulns/CVE-2025-66511
Aliases
  • GHSA-whm3-vv55-gf27
Published
2025-12-05T16:42:30.236Z
Modified
2026-04-02T13:02:24.552975Z
Severity
  • 4.8 (Medium) CVSS_V3 - CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N CVSS Calculator
Summary
Nextcloud Calendar app used predictable proposal participant tokens
Details

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.

Database specific
{
    "cwe_ids": [
        "CWE-330"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/66xxx/CVE-2025-66511.json",
    "cna_assigner": "GitHub_M"
}
References

Affected packages

Git / github.com/nextcloud/calendar

Affected ranges

Type
GIT
Repo
https://github.com/nextcloud/calendar
Events

Affected versions

v6.*
v6.0.0
v6.0.0-rc.1
v6.0.0-rc.2
v6.0.0-rc.3
v6.0.0-rc.4
v6.0.0-rc.5
v6.0.0-rc.6
v6.0.1
v6.0.2

Database specific

source
"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2025-66511.json"