Low

Missing Authorization in GitLab CE/EE custom role member management

IdentifiersCVE-2026-4916CWE-862· Missing Authorization

CVE-2026-4916 is a missing authorization vulnerability in GitLab Community Edition and Enterprise Edition. It affects all versions from 18.2 before 18.8.9, 18.9 before 18.9.5, and 18.10 before 18.10.3. Due to improper authorization checks in group member management operations tied to custom role permissions, an authenticated user assigned a custom role could perform unauthorized member-management actions against higher-privileged group members, specifically demoting or removing them.

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ANALYST BRIEF

Impact, mitigation & remediation

What it means. What to do now. Patch path, mitigations, and the assume-compromise checklist.

Impact

What an attacker gets, and what they’ve been doing with it.

Successful exploitation could allow an authenticated attacker with a custom role to alter group membership in ways that should be restricted, including demoting or removing higher-privileged members. This can undermine group administration integrity, disrupt access control, and potentially facilitate further privilege abuse or operational disruption within affected GitLab groups.

Mitigation

If you can’t patch tonight, do this now.

If immediate patching is not possible, restrict or review assignment of custom roles that include member-management capabilities, especially in groups containing higher-privileged owners or maintainers. Audit group membership changes for unauthorized demotions or removals, minimize delegation of member-management permissions, and limit access to affected self-managed instances until upgrades can be applied. GitLab.com was already patched, and GitLab Dedicated customers did not need to take action per the provided content.

Remediation

Patch, then assume compromise.

Upgrade GitLab CE/EE to a fixed release: 18.8.9 or later in the 18.8 series, 18.9.5 or later in the 18.9 series, or 18.10.3 or later in the 18.10 series. GitLab stated these patch releases remediate the improper authorization checks affecting custom role member management operations.

PUBLIC EXPLOITS

Exploits

No public exploits tracked yet. Mallory keeps watching.

VALID 0 / 0 TOTALView more in app

No public exploit code observed for this vulnerability.

EXPOSURE SURFACE

Affected products & vendors

Products and vendors Mallory has correlated with this vulnerability. Open in Mallory to drill down to specific CPE configurations and version ranges.

VendorProductType

GitLabGitlabapplication

Vendor-confirmed product mapping. Mallory continuously reconciles this list against your asset inventory.

ACTIVITY FEED

Recent activity

5 sources tracked across advisories, community write-ups, and news. New activity surfaces here as Mallory finds it.

5 SOURCESView more in app

thecyberexpress com vulnerabilitiesNews

Apr 10, 2026

GitLab Security Update Fixes CVE-2026-5173 Flaw

A low-severity GitLab vulnerability involving missing authorization checks in custom role permissions.

cyber security newsNews

Apr 9, 2026

GitLab Patches Multiple Vulnerabilities That Enables DoS and Code Injection Attacks

A lower-severity GitLab authorization vulnerability caused by a missing authorization check that lets users with custom roles demote or remove higher-privileged group members.

gitlab releasesNews

Apr 8, 2026

GitLab Patch Release: 18.10.3, 18.9.5, 18.8.9 | GitLab

A missing authorization vulnerability in GitLab CE/EE custom role permissions that could allow an authenticated user to demote or remove higher-privileged group members.

docs gitlabNews

Oct 1, 2018

GitLab Patch Release: 18.10.3, 18.9.5, 18.8.9 | GitLab Docs

A missing authorization vulnerability in GitLab custom role permissions that could allow a user to demote or remove higher-privileged group members.

What this page doesn’t show

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Exposure mapping

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Threat actor evidence

Every observed campaign linking this CVE to a named adversary.

Associated malware

Malware families riding this exploit, with evidence and IOCs.

Detection signatures

YARA, Sigma, Snort, and vendor rules, auto-deployed to your SIEM.

Vendor-by-vendor mapping

Cross-references every affected SKU, including bundled OEM variants.

Social activity1