Low severity · published Jun 1, 2026
CVE-2026-45159
Nextcloud: Files drop share links for end-to-end encrypted folders allowed to drop files into other folders of the share owner
3.5
CVSS
0.2%
EPSS
No
On KEV
Description
Nextcloud is an open source content collaboration platform. From versions 1.15.0 to before 1.15.4, 1.16.0 to before 1.16.3, 1.17.0 to before 1.17.1, and 1.18.0 to before 1.18.1, a malicious user with access to an end-to-end encrypted files drop link was able to also drop files into other end-to-end encrypted folders of the share owner. Reading and modifying of other files was not possible. This issue has been patched in versions 1.15.4, 1.16.3, 1.17.1, 1.18.1, and 2.0.0-rc.7.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:L/A:N
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
Required
Confidentiality
None
Integrity
Low
Availability
None
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.2% · higher than 10% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
SE
security-advisories · nextcloud
>= 1.15.0, < 1.15.4; >= 1.16.0, < 1.16.3; >= 1.17.0, < 1.17.1; >= 1.18.0, < 1.18.1 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-45159
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-45159
github.com
https://github.com/nextcloud/end_to_end_encryption/pull/1395
github.com
https://github.com/nextcloud/security-advisories/security/advisories/GHSA-p3qw-7gwx-wg24
hackerone.com
https://hackerone.com/reports/3304830
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