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CVE-2026-45155

Nextcloud: Private circle can be added to another circle via API

Published: Jun 1, 2026Updated: Jun 1, 2026 Sources: CVE List NVD
NVD MITRE
2.6CVSS
LOW

Nextcloud is an open source content collaboration platform. In Nextcloud Server from versions 32.0.0 to before 32.0.7 and 33.0.0 to before 33.0.1, a missing access check on API level allowed to add unknown circles by their ID directly to other circles. Since circle IDs have 62^15 complexity by default this is still unlikely to be executable at will, but if access to an ID was available via another source, memberships could be tracked like this. It is recommended that the Nextcloud Server is upgraded to 32.0.7 or 33.0.1. It is recommended that the Nextcloud Enterprise Server is upgraded to 29.0.16.14, 30.0.17.8, 31.0.14.3, 32.0.7 or 33.0.1

EPSS Score
N/A
CISA KEV
Not in KEV
Exploits
No Known Exploits
Remediation
No Fix Available

CVSS Vector Breakdown

AV:NAC:HPR:LUI:RS:UC:LI:NA:N
Exploitability
AV:NAttack Vector
Network
AC:HAttack Complexity
High
PR:LPrivileges Required
Low
UI:RUser Interaction
Required
Scope
S:UScope
Unchanged
Impact
C:LConfidentiality
Low
I:NIntegrity
None
A:NAvailability
None

Weaknesses

CWE-639

Affected Products

security-advisories
nextcloud

Attack Graph

Products CVE Techniques Tactics

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Exploitability

No known exploits, KEV entries, or remediation guidance available for this vulnerability yet.

MITRE ATT&CK

1 technique
Initial Access
View detailed technique mapping

References

https://github.com/nextcloud/security-advisories/security/advisories/GHSA-xpgv-grf9-gm7x
github.com
https://github.com/nextcloud/circles/pull/2401
github.com
https://hackerone.com/reports/3511998
hackerone.com

Timeline

Published
Jun 1, 2026
Last Updated
Jun 1, 2026

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