CVE-2026-45159 Missing authorization in security-advisories
A malicious user with a file drop link can upload files to other encrypted folders of the share owner, bypassing intended access restrictions.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- None listed
What is CVE-2026-45159?
CVE-2026-45159 is a low-severity missing authorization vulnerability in nextcloud security-advisories, published on 1 Jun 2026. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.
Official 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.
Weakness: CWE-639
Which versions are affected by CVE-2026-45159?
How do I fix CVE-2026-45159?
No fix has been published for CVE-2026-45159 yet. Limit exposure of the affected software until one is available.
Upgrade, and check permissions on every request on the server, not only in the interface. More about Missing authorization.
Is CVE-2026-45159 being exploited?
There is no known exploitation of CVE-2026-45159 in the wild and no public exploit code.
Sources
Also known as GHSA-p3qw-7gwx-wg24.