CVE-2026-45543 Missing authorization in security-advisories
Removed collaborators retain unauthorized read access to uploaded form response files due to lingering share permissions.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-45543?
CVE-2026-45543 is a medium-severity missing authorization vulnerability in nextcloud security-advisories, published on 1 Jun 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
Nextcloud is an open source content collaboration platform. From version 4.3.0 to before version 5.2.7, a removed collaborator retains unauthorized read access to uploaded respondent files for the affected form. The scope is limited to uploaded files for forms where that user previously had results access. This issue has been patched in version 5.2.7.
Weakness: CWE-552
Which versions are affected by CVE-2026-45543?
It affects 1 product.
Products include Nextcloud Forms.
How do I fix CVE-2026-45543?
No fix has been published for CVE-2026-45543 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-2026-45543 being exploited?
There is no known exploitation of CVE-2026-45543 in the wild and no public exploit code.
Sources
Also known as GHSA-q4fw-6jf8-5vhh.