CVE-2019-20890 Security feature bypass in n/a
Attackers can bypass email address discovery restrictions in Mattermost Server, potentially exposing user contact information.
- 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-2019-20890?
CVE-2019-20890 is a medium-severity 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 5.7. It allows a bypass of e-mail address discovery restrictions.
Which versions are affected by CVE-2019-20890?
It affects 1 product.
Products include Mattermost Mattermost Server.
How do I fix CVE-2019-20890?
No fix has been published for CVE-2019-20890 yet. Limit exposure of the affected software until one is available.
Is CVE-2019-20890 being exploited?
There is no known exploitation of CVE-2019-20890 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-vxm4-w9mc-pm8x.