CVE-2026-45281Nextcloud is an open source content collaboration platform.
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No exploitation reported and no EPSS estimate yet.
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Nextcloud is an open source content collaboration platform. In Nextcloud Server from versions 32.0.0 to before 32.0.9, and 33.0.0 to before 33.0.3, with the knowledge of other users’ principal URL an attacker could possibly send a request to gain full access to their calendar. Therefore, the attacker must be an authenticated user. This is because of improper authorization controls in the backend of the calendar. If the attacker had access to the calendar, they would be able to view and modify it. It is recommended that the Nextcloud Server is upgraded to 33.0.3 or 32.0.9. It is recommended that the Nextcloud Enterprise Server is upgraded to 33.0.3, 32.0.9, 31.0.14.5, 30.0.17.9, 29.0.16.16, 28.0.14.17, 27.1.11.26, 26.0.13.26, 25.0.13.29, 24.0.12.34, 23.0.12.35, 22.2.10.39, or 21.0.9.23
- CVSS
- 8.1 HIGH (v3.1, NVD)CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N
- Weakness (CWE)
- CWE-639
- Known exploited
- Not in CISA's KEV catalog
- EPSS (exploitation in the next 30 days)
- Not loaded for this CVE
- Assigned by
- Not given
- NVD analysis
- Analyzed
- Record last updated
- Jul 22, 2026
- First seen by InfoSec Signals
- Oct 9, 2026
Affected products
nextcloud nextcloud_server nextcloud:nextcloud_server | from 32.0.0 before 32.0.9; from 33.0.0 before 33.0.3; from 21.0.0 before 21.0.9.23; from 22.0.0 before 22.2.10.39; from 23.0.0 before 23.0.12.35; from 24.0.0 before 24.0.12.34; from 25.0.0 before 25.0.13.29; from 26.0.0 before 26.0.13.26; and 7 more ranges | NVD |
References
- https://github.com/nextcloud/security-advisories/security/advisories/GHSA-hrrv-mp25-26vvmitigation, vendor-advisory
- https://github.com/nextcloud/server/pull/59962issue-tracking, patch
- https://hackerone.com/reports/3545964permissions-required
The CVE record on cve.org NVD's entry
The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.