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CVE-2026-45283: Nextcloud is an open source content collaboration platform

25
Routine
MEDIUM 6.3UPGRADE

CVE-2026-45283 is a medium-severity flaw (CVSS 6.3) affecting nextcloud server. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Nextcloud is an open source content collaboration platform. In Nextcloud Server from versions 32.0.0 to before 32.0.2, and 33.0.0 to before 33.0.1, the files_lock app did not properly validate the ownership of files when processing DAV lock and unlock requests. An authenticated user could lock or unlock files belonging to other users by targeting their absolute WebDAV paths. Additionally, lock tokens were disclosed to unauthorized callers in erro

Why this priority

  • No elevated risk signals yet

A fixed release or distro patch exists.

Risk facts

CVSS score6.3 (Medium)
Attack vectorNetwork (remote)
Attack complexityLow
Privileges neededLow
User interactionNone
EPSS exploit chance0.2% (top 89%)
CISA exploited listNo
WeaknessCWE-287
Published2026-06-01
Last modified2026-07-22
Publisher (CNA): GitHub, Inc. · Vendor: nextcloud

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Last updated 2026-07-22 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

nextcloud nextcloud server UPGRADE
Affected: >= 32.0.0 and < 32.0.2 · >= 33.0.0 and < 33.0.1 · >= 31.0.0 and < 31.0.14.4
Fixed in: 31.0.14.4, 32.0.2, 33.0.1
Safe to downgrade to: a release before 31.0.0
1. Check installed version
apt-cache policy nextcloud-server || rpm -q nextcloud-server || nextcloud-server --version
2. UPGRADE to 31.0.14.4 (Debian / Ubuntu)
sudo apt update && sudo apt install --only-upgrade nextcloud-server
2. UPGRADE (RHEL / Amazon Linux / Fedora)
sudo dnf upgrade nextcloud-server
Note
Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.
3. If no update is available yet, DOWNGRADE to a release before 31.0.0 (Debian / Ubuntu)
apt-cache madison nextcloud-server sudo apt install nextcloud-server=<VERSION_BEFORE_31.0.0> sudo apt-mark hold nextcloud-server
3. If no update is available yet, DOWNGRADE (RHEL / Amazon Linux / Fedora)
dnf --showduplicates list nextcloud-server sudo dnf downgrade nextcloud-server-<VERSION_BEFORE_31.0.0> sudo dnf versionlock add nextcloud-server
Downgrade risk
Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.
After downgrade
Restart the service, and keep the package held until a fixed release ships.
Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-45283?

nextcloud server: upgrade to 31.0.14.4, 32.0.2, 33.0.1. Exact commands for each OS are on this page.

Is CVE-2026-45283 being exploited?

CVE-2026-45283 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-45283 affect?

CVE-2026-45283 affects nextcloud server. Severity is medium (CVSS 6.3). Nextcloud is an open source content collaboration platform. In Nextcloud Server from versions 32.0.0 to before 32.0.2, and 33.0.0 to before 33.0.1, the files_lock app did not properly validate the ownership of files when processing DAV lock

How urgent is CVE-2026-45283?

Priority 25/100. No elevated risk signals yet.

Software pages

Nextcloud vulnerabilities

Related CVEs

References

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