CVE-2016-11084 Mattermost Server allows XSS via CSRF
An attacker can execute arbitrary scripts in a victim's browser via CSRF, potentially leading to session hijacking or data theft.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- Available
What is CVE-2016-11084?
CVE-2016-11084 is a medium-severity cross-site scripting vulnerability in Mattermost Mattermost Server, published on 19 Jun 2020. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Official description
An issue was discovered in Mattermost Server before 2.1.0. It allows XSS via CSRF.
Weakness: CWE-352
Which versions are affected by CVE-2016-11084?
3 open source packages ship an affected version, including github.com/mattermost/mattermost-server. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
github.com/mattermost/mattermost-server Go | All versions | 2.1.0 |
github.com/mattermost/mattermost-server Go | All versions | 2.1.0 |
github.com/mattermost/mattermost-server Go | All versions | 2.1.0+incompatible |
Products include Mattermost Mattermost Server.
How do I fix CVE-2016-11084?
Upgrade github.com/mattermost/mattermost-server to a fixed version for your release line: 2.1.0 or 2.1.0+incompatible.
Escape output for the context it lands in and set a strict Content Security Policy. Upgrading the affected component is the real fix. More about Cross-site scripting.
Is CVE-2016-11084 being exploited?
There is no known exploitation of CVE-2016-11084 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-vw57-55f8-c73q, GO-2025-4066.