CVE-2025-59788: Cross-site scripting (XSS) vulnerability in a reachable files_pdfviewer example directory in Nextcloud with ve

Routine

MEDIUM 6.4UPGRADE

CVE-2025-59788 is a medium-severity flaw (CVSS 6.4) affecting nextcloud server. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Cross-site scripting (XSS) vulnerability in a reachable files_pdfviewer example directory in Nextcloud with versions before 22.2.10.33, 23.0.12.29, 24.0.12.28, 25.0.13.23, 26.0.13.20, 27.1.11.20, 28.0.14.11, 29.0.16.8, 30.0.17, 31.0.10, and 32.0.1 allows attackers to execute arbitrary JavaScript in the context of a user's browser via a crafted PDF file to viewer.html. This issue is related to CVE-2024-4367, but the root cause of this Nextcloud is

Why this priority

Public exploit reference

A fixed release or distro patch exists.

Risk facts

CVSS score	6.4 (Medium)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	Low
User interaction	None
EPSS exploit chance	0.3% (top 77%)
CISA exploited list	No
Weakness	CWE-749, CWE-79
Published	2025-12-04
Last modified	2026-10-18

Publisher (CNA): MITRE · Vendor: nextcloud

Last updated 2026-10-18 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2025-12-04 19:16 UTCPublished CVE record published
2026-10-18 15:10 UTCUpdated Record last modified

nextcloud nextcloud server UPGRADE

Affected: >= 30.0.0 and < 30.0.17 · >= 31.0.0 and < 31.0.10 · >= 32.0.0 and < 32.0.1 · >= 22.0.0 and < 22.2.10.33 · >= 23.0.0 and < 23.0.12.29 · >= 24.0.0 and < 24.0.12.28 · >= 25.0.0 and < 25.0.13.23 · >= 26.0.0 and < 26.0.13.20

Fixed in: 22.2.10.33, 23.0.12.29, 24.0.12.28, 25.0.13.23, 26.0.13.20, 27.1.11.20, 28.0.14.11, 29.0.16.8, 30.0.17, 31.0.10, 32.0.1

Safe to downgrade to: a release before 22.0.0

1. Check installed version

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

2. UPGRADE to 22.2.10.33 (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 22.0.0 (Debian / Ubuntu)

apt-cache madison nextcloud-server sudo apt install nextcloud-server=<VERSION_BEFORE_22.0.0> 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_22.0.0> 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-2025-59788?

nextcloud server: upgrade to 22.2.10.33, 23.0.12.29, 24.0.12.28, 25.0.13.23, 26.0.13.20, 27.1.11.20, 28.0.14.11, 29.0.16.8, 30.0.17, 31.0.10, 32.0.1. Exact commands for each OS are on this page.

Is CVE-2025-59788 being exploited?

CVE-2025-59788 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-2025-59788 affect?

CVE-2025-59788 affects nextcloud server. Severity is medium (CVSS 6.4). Cross-site scripting (XSS) vulnerability in a reachable files_pdfviewer example directory in Nextcloud with versions before 22.2.10.33, 23.0.12.29, 24.0.12.28, 25.0.13.23, 26.0.13.20, 27.1.11.20, 28.0.14.11, 29.0.16.8, 30.0.17, 31.0.10, and

How urgent is CVE-2025-59788?

Priority 33/100. Public exploit reference

Software pages

Nextcloud vulnerabilities

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References

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