CVE-2022-1337 OOM DoS in Mattermost image proxy
An authenticated attacker can crash the Mattermost server by requesting links to very large image files, causing an out-of-memory condition.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2022-1337?
CVE-2022-1337 is a medium-severity denial of service vulnerability in Mattermost Mattermost Server, published on 13 Apr 2022. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
The image proxy component in Mattermost version 6.4.1 and earlier allocates memory for multiple copies of a proxied image, which allows an authenticated attacker to crash the server via links to very large image files.
Which versions are affected by CVE-2022-1337?
6 open source packages ship an affected version, including github.com/mattermost/mattermost-server/v6, mattermost and github.com/mattermost/mattermost-server. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
github.com/mattermost/mattermost-server/v6 Go | All versions | 6.4.2 |
github.com/mattermost/mattermost-server/v6 Go | All versions | 6.4.2 |
github.com/mattermost/mattermost-server/v6 Go | All versions | 6.4.2 |
mattermost Bitnami | From 5.37.0 | 5.37.9, 6.2.5, 6.3.5, 6.4.2 |
github.com/mattermost/mattermost-server Go | All versions | None |
github.com/mattermost/mattermost-server/v5 Go | All versions | None |
Products include Mattermost Mattermost Server.
How do I fix CVE-2022-1337?
Upgrade github.com/mattermost/mattermost-server/v6 to 6.4.2 or later.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2022-1337 being exploited?
There is no known exploitation of CVE-2022-1337 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 BIT-mattermost-2022-1337, GHSA-f37q-q7p2-ccfc, GO-2022-0595.