CVE-2026-5816: GitLab has remediated an issue in GitLab CE/EE affecting all versions from 18.10 before 18.10.4 and 18.11 befo

Routine

HIGH 8.0UPGRADE

CVE-2026-5816 is a high-severity flaw (CVSS 8.0) affecting gitlab. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

GitLab has remediated an issue in GitLab CE/EE affecting all versions from 18.10 before 18.10.4 and 18.11 before 18.11.1 that could have allowed an unauthenticated user to execute arbitrary JavaScript in a user's browser session due to improper path validation under certain conditions.

Why this priority

High severity

A fixed release or distro patch exists.

Risk facts

CVSS score	8.0 (High)
Attack vector	Network (remote)
Attack complexity	High
Privileges needed	None
User interaction	Required
EPSS exploit chance	0.4% (top 65%)
CISA exploited list	No
Weakness	CWE-41
Published	2026-04-22
Last modified	2026-06-17

Publisher (CNA): GitLab Inc. · Vendor: gitlab

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

Am I affected?

Timeline

2026-04-22 17:16 UTCPublished CVE record published
2026-06-17 10:59 UTCUpdated Record last modified

gitlab gitlab UPGRADE

Affected: >= 18.10.0 and < 18.10.4 · 18.11.0

Fixed in: 18.10.4

Safe to downgrade to: a release before 18.10.0

1. Check installed version

apt-cache policy gitlab || rpm -q gitlab || gitlab --version

2. UPGRADE to 18.10.4 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade gitlab

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade gitlab

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 18.10.0 (Debian / Ubuntu)

apt-cache madison gitlab sudo apt install gitlab=<VERSION_BEFORE_18.10.0> sudo apt-mark hold gitlab

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

dnf --showduplicates list gitlab sudo dnf downgrade gitlab-<VERSION_BEFORE_18.10.0> sudo dnf versionlock add gitlab

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-2026-5816?

gitlab: upgrade to 18.10.4. Exact commands for each OS are on this page.

Is CVE-2026-5816 being exploited?

CVE-2026-5816 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-2026-5816 affect?

CVE-2026-5816 affects gitlab. Severity is high (CVSS 8.0). GitLab has remediated an issue in GitLab CE/EE affecting all versions from 18.10 before 18.10.4 and 18.11 before 18.11.1 that could have allowed an unauthenticated user to execute arbitrary JavaScript in a user's browser session due to impr

How urgent is CVE-2026-5816?

Priority 37/100. High severity

Software pages

GitLab vulnerabilities

Related CVEs

CVE-2026-15723 HIGH 8.2 UPGRADE GitLab has remediated an issue in GitLab CE/EE affecting all versions from 10.1 before 19.3.6, 19.4 before 19.
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CVE-2026-12664 MEDIUM 6.8 UPGRADE GitLab has remediated an issue in GitLab CE/EE affecting all versions from 18.2 before 19.3.6, 19.4 before 19.
CVE-2026-112326 LOW 3.1 UPGRADE GitLab has remediated an issue in GitLab EE affecting all versions from 17.8 before 19.3.6, 19.4 before 19.4.3
CVE-2026-112212 HIGH 7.5 UPGRADE GitLab has remediated an issue in GitLab CE/EE affecting all versions from 18.3 before 19.3.6, 19.4 before 19.

References

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