CVE-2019-20879 Auth bypass in n/a
Attackers can change email addresses without re-authentication, potentially leading to account takeover in Mattermost Server.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2019-20879?
CVE-2019-20879 is a medium-severity authentication bypass vulnerability in Mattermost Mattermost Server, published on 19 Jun 2020. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
An issue was discovered in Mattermost Server before 5.8.0, 5.7.2, 5.6.5, and 4.10.7. Changes to e-mail addresses do not require credential re-entry.
Weakness: CWE-287
Which versions are affected by CVE-2019-20879?
It affects 1 product.
Products include Mattermost Mattermost Server.
How do I fix CVE-2019-20879?
No fix has been published for CVE-2019-20879 yet. Limit exposure of the affected software until one is available.
Upgrade, and rotate credentials and sessions that may have been exposed. More about Authentication bypass.
Is CVE-2019-20879 being exploited?
There is no known exploitation of CVE-2019-20879 in the wild and no public exploit code.
Other vulnerabilities in Mattermost Mattermost Server
- CVE-2025-12419 Account takeover on OAuth/OpenID-enabled servers
- CVE-2025-12421 Account Takeover via Code Exchange Endpoint
- CVE-2025-4981 Path Traversal Leading to RCE by Any Authenticated Mattermost User
- CVE-2025-20051 Arbitrary file read via block duplication in Mattermost Boards
- CVE-2025-25279 Arbitrary file read in Mattermost Boards via import & export board archive
Sources
Also known as GHSA-gfp2-563m-jgqr.