CVE-2020-8118: An authenticated server-side request forgery in Nextcloud server 16.0.1 allowed to detect local and remote ser

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MEDIUM 5.0WATCHLISTUPGRADEDOWNGRADEMITIGATE

CVE-2020-8118 is a medium-severity flaw (CVSS 5.0) affecting nextcloud server, backports sle, suse linux enterprise server. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

An authenticated server-side request forgery in Nextcloud server 16.0.1 allowed to detect local and remote services when adding a new subscription in the calendar application.

Why this priority

Public exploit reference
On your watchlist

A fixed release or distro patch exists.

Risk facts

CVSS score	5.0 (Medium)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	Low
User interaction	None
EPSS exploit chance	1.3% (top 30%)
CISA exploited list	No
Weakness	CWE-918
Published	2020-02-04
Last modified	2026-06-17

Publisher (CNA): HackerOne · Vendor: nextcloud · novell · opensuse

Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2020-02-04 20:15 UTCPublished CVE record published
2026-06-17 03:25 UTCUpdated Record last modified

nextcloud nextcloud server UPGRADE

Affected: < 15.0.9 · >= 16.0.0 and < 16.0.2

Fixed in: 15.0.9, 16.0.2

Safe to downgrade to: a release before 16.0.0

1. Check installed version

apt-cache policy nextcloud-server || rpm -q nextcloud-server || nextcloud-server --version

2. UPGRADE to 15.0.9 (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 16.0.0 (Debian / Ubuntu)

apt-cache madison nextcloud-server sudo apt install nextcloud-server=<VERSION_BEFORE_16.0.0> 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_16.0.0> 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.

opensuse backports sle DOWNGRADE

Affected: 15.0 sp1

Fixed in: no fixed release known

Safe to downgrade to: a release before 15.0

1. Check installed version

apt-cache policy backports-sle || rpm -q backports-sle || backports-sle --version

2. No fixed release: DOWNGRADE to a release before 15.0 (Debian / Ubuntu)

apt-cache madison backports-sle sudo apt install backports-sle=<VERSION_BEFORE_15.0> sudo apt-mark hold backports-sle

2. No fixed release: DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list backports-sle sudo dnf downgrade backports-sle-<VERSION_BEFORE_15.0> sudo dnf versionlock add backports-sle

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.

novell suse linux enterprise server MITIGATE

Affected: 12.0

Fixed in: no fixed release known

Safe to downgrade to: a release before 12.0

Check your OS release

cat /etc/os-release; uname -r

Debian / Ubuntu

sudo apt update && sudo apt full-upgrade

RHEL / Amazon Linux / Fedora

sudo dnf upgrade --refresh

Windows

Install the latest cumulative update from Windows Update

If no patch exists yet

OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.

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-2020-8118?

nextcloud server: upgrade to 15.0.9, 16.0.2; backports sle: downgrade or apply the listed mitigation; suse linux enterprise server: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2020-8118 being exploited?

CVE-2020-8118 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-2020-8118 affect?

CVE-2020-8118 affects nextcloud server, backports sle, suse linux enterprise server. Severity is medium (CVSS 5.0). An authenticated server-side request forgery in Nextcloud server 16.0.1 allowed to detect local and remote services when adding a new subscription in the calendar application.

How urgent is CVE-2020-8118?

Priority 45/100. Public exploit reference; On your watchlist

Software pages

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References

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