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Fencer Vulns
medium 4.3

CVE-2026-45264 json

Nextcloud: ACL Rename Permission Bypass in Team Folders Allows Unauthorized File Renames

published 2026-06-01 5 mo ago modified 2026-07-22 3 mo ago also EUVD-2026-33671

cvss
4.3
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 13%
public exploits
0
none known

Summary

Nextcloud is an open source content collaboration platform. From versions 17.0.0 to before 17.0.15, 18.0.0 to before 18.1.12, 19.0.0 to before 19.1.16, 20.0.0 to before 20.1.11, and 21.0.0 to before 21.0.4, a user with READ and CREATE permission, but no UPDATE permission for a team folder can rename files in the team folder. This issue has been patched in versions 17.0.15, 18.1.12, 19.1.16, 20.1.11, and 21.0.4.

Patch / fix

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
5 mo ago

Exploit prediction

0.23% chance of exploitation in the next 30 days, higher than 13% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 4.3 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N

Affected products

  • nextcloud security-advisories

Classification

Weakness

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.