CVE-2026-45157 Nextcloud: Valid share tokens allow to access tempory upload files of share owner
Attackers with valid share tokens can access temporary upload files of the share owner, exposing sensitive data during ongoing uploads.
- 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
- Available
What is CVE-2026-45157?
CVE-2026-45157 is a medium-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. In Nextcloud Server from versions 32.0.0 to before 32.0.9, and 33.0.0 to before 33.0.3, when a malicious user has access to a file share of a user, they could use this share token to also access the chunking upload directly and see temporary part files during on going uploads. It is recommended that the Nextcloud Server is upgraded to 32.0.9 or 33.0.3. It is recommended that the Nextcloud Enterprise Server is upgraded to 26.0.13.26, 27.1.11.25, 28.0.14.17, 29.0.16.16, 30.0.17.9, 31.0.14.5, 32.0.9 or 33.0.3
Weakness: CWE-284
Which versions are affected by CVE-2026-45157?
1 open source package ship an affected version, including nextcloud.
| Package | Affected | Fixed in |
|---|---|---|
nextcloud Bitnami | From 32.0.0 | 32.0.9, 33.0.3 |
How do I fix CVE-2026-45157?
Upgrade nextcloud to a fixed version for your release line: 32.0.9 or 33.0.3.
Upgrade, and check permissions on every request on the server, not only in the interface. More about Missing authorization.
Is CVE-2026-45157 being exploited?
There is no known exploitation of CVE-2026-45157 in the wild and no public exploit code.
Sources
Also known as BIT-nextcloud-2026-45157, GHSA-45pj-p7x7-4mhc.