CVE-2021-39896 Auth bypass in GitLab
An admin may remain logged in as a second impersonated user after stopping impersonation, leading to repudiation issues and unauthorized access.
- Exploited in the wild
- Not known
- Login needed
- An administrator
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2021-39896?
CVE-2021-39896 is a low-severity authentication bypass vulnerability in Gitlab Gitlab, published on 4 Oct 2021. An attacker needs administrator access to exploit it, with no action from the victim.
Official description
In all versions of GitLab CE/EE since version 8.0, when an admin uses the impersonate feature twice and stops impersonating, the admin may be logged in as the second user they impersonated, which may lead to repudiation issues.
Which versions are affected by CVE-2021-39896?
1 open source package ship an affected version, including gitlab. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
gitlab Bitnami | From 8.0.0 | 14.1.7, 14.2.5, 14.3.1 |
Products include Gitlab Gitlab.
How do I fix CVE-2021-39896?
Upgrade gitlab to a fixed version for your release line: 14.1.7, 14.2.5 or 14.3.1.
Upgrade, and rotate credentials and sessions that may have been exposed. More about Authentication bypass.
Is CVE-2021-39896 being exploited?
There is no known exploitation of CVE-2021-39896 in the wild and no public exploit code.
Other vulnerabilities in Gitlab Gitlab
- CVE-2026-97229 GitLab Community Edition and Enterprise Edition Integer Overflow or Wraparound
- CVE-2026-85706 GitLab Community Edition and Enterprise Edition Path Traversal
- CVE-2023-7028 GitLab Community and Enterprise Editions Improper Access Control
- CVE-2021-22205 GitLab Community and Enterprise Editions Remote Code Execution
- CVE-2021-39935 GitLab Community and Enterprise Editions Server-Side Request Forgery (SSRF)
Sources
Also known as BIT-gitlab-2021-39896, GHSA-4ccf-v4wp-c858, UBUNTU-CVE-2021-39896.