CVE-2026-45284: Nextcloud is an open source content collaboration platform

Routine

MEDIUM 4.6UPGRADE

CVE-2026-45284 is a medium-severity flaw (CVSS 4.6) affecting user oidc. 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. From version 1.3.6 to before version 8.4.0, an improper check allowed users that where provided by LDAP to still authenticate towards user OIDC after they where deleted. This issue has been patched in version 8.4.0.

Why this priority

No elevated risk signals yet

A fixed release or distro patch exists.

Risk facts

CVSS score	4.6 (Medium)
Attack vector	Network (remote)
Attack complexity	High
Privileges needed	Low
User interaction	Required
EPSS exploit chance	0.2% (top 91%)
CISA exploited list	No
Weakness	CWE-284
Published	2026-06-01
Last modified	2026-07-22

Publisher (CNA): GitHub, Inc. · Vendor: nextcloud

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

Am I affected?

Timeline

2026-06-01 19:16 UTCPublished CVE record published
2026-07-22 08:10 UTCUpdated Record last modified

nextcloud user oidc UPGRADE

Affected: >= 1.3.6 and < 8.4.0

Fixed in: 8.4.0

Safe to downgrade to: a release before 1.3.6

1. Check installed version

apt-cache policy user-oidc || rpm -q user-oidc || user-oidc --version

2. UPGRADE to 8.4.0 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade user-oidc

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade user-oidc

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 1.3.6 (Debian / Ubuntu)

apt-cache madison user-oidc sudo apt install user-oidc=<VERSION_BEFORE_1.3.6> sudo apt-mark hold user-oidc

3. If no update is available yet, DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list user-oidc sudo dnf downgrade user-oidc-<VERSION_BEFORE_1.3.6> sudo dnf versionlock add user-oidc

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-2026-45284?

user oidc: upgrade to 8.4.0. Exact commands for each OS are on this page.

Is CVE-2026-45284 being exploited?

CVE-2026-45284 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-2026-45284 affect?

CVE-2026-45284 affects user oidc. Severity is medium (CVSS 4.6). Nextcloud is an open source content collaboration platform. From version 1.3.6 to before version 8.4.0, an improper check allowed users that where provided by LDAP to still authenticate towards user OIDC after they where deleted. This issue

How urgent is CVE-2026-45284?

Priority 18/100. No elevated risk signals yet.

Software pages

Nextcloud vulnerabilities

Related CVEs

CVE-2026-45278 LOW 3.3 UPGRADE Nextcloud is an open source content collaboration platform

References

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