GO-2025-3482 CVE-2025-1412 GHSA-rhvr-6w8c-6v7w

Mattermost fails to invalidate all active sessions when converting a user to a bot in github.com/mattermost/mattermost-server

High Go

Severity: 8.8 / 10; High · CVSS 3.1
Exploit chance (EPSS): 0.26%; Chance of exploitation in the next 30 days. Higher than 17.41% of scored vulnerabilities.
Known exploited: No; Not in CISA's catalog
Weakness: CWE-384 Session Fixation
Fix: Available; 2 packages have a fixed version

Description

Affected versions

Go

Package	Vulnerable	Fixed in
github.com/mattermost/mattermost-server	`>= 9.11.0-rc1+incompatible, < 9.11.7+incompatible` `>= 10.4.0-rc1+incompatible, < 10.4.2+incompatible`	`9.11.7+incompatible` `10.4.2+incompatible`
github.com/mattermost/mattermost-server/v5	`all versions`	No fix yet
github.com/mattermost/mattermost-server/v6	`all versions`	No fix yet
github.com/mattermost/mattermost/server/v8	`< 8.0.0-20241217145510-faa7e4f2ea0c`	`8.0.0-20241217145510-faa7e4f2ea0c`
github.com/mattermost/mattermost/server/v8	`>= 10.4.0-rc1, < 10.4.2`	`10.4.2`
github.com/mattermost/mattermost/server/v8	`>= 9.11.0-rc1, < 9.11.7`	`9.11.7`

How to fix

Move to the fixed version or later with your package manager, update the lockfile, and run your tests. If the package only arrives through another dependency, upgrade that dependency first. If none of its releases pulls a fixed version yet, force the version with your package manager's override.

github.com/mattermost/mattermost-server Go → `10.4.2+incompatible`

go

go get github.com/mattermost/mattermost-server@v10.4.2+incompatible && go mod tidy

github.com/mattermost/mattermost/server/v8 Go → `8.0.0-20241217145510-faa7e4f2ea0c`

go

go get github.com/mattermost/mattermost/server/v8@v8.0.0-20241217145510-faa7e4f2ea0c && go mod tidy

Severity breakdown

CVSS 3.1 8.8

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Attack vector: Network
Attack complexity: Low
Privileges required: Low
User interaction: None
Scope: Unchanged
Confidentiality: High
Integrity: High
Availability: High

Weakness

CWE-384: Session Fixation

Authenticating a user, or otherwise establishing a new user session, without invalidating any existing session identifier gives an attacker the opportunity to steal authenticated sessions.

How to prevent it

Architecture and Design: Invalidate any existing session identifiers prior to authorizing a new user session.
Architecture and Design: For platforms such as ASP that do not generate new values for sessionid cookies, utilize a secondary cookie. In this approach, set a secondary cookie on the user's browser to a random value and set a session variable to the same value. If the session variable and the cookie value ever don't match, invalidate the session, and force the user to log on again.
Operation: Use an application firewall that can detect attacks against this weakness. It can be beneficial in cases in which the code cannot be fixed (because it is controlled by a third party), as an emergency prevention measure while more comprehensive software assurance measures are applied, or to provide defense in depth [REF-1481].

References

Advisories

Packages

github.com/mattermost/mattermost

Timeline

Feb 24, 2025 Published
Sep 10, 2026 Last updated by the source
Oct 31, 2026 Latest EPSS score

Advisory	Severity	Why it's related
GHSA-xmfh-3ccg-c9fx Mattermost has an Incorrect Authorization issue	Low	Also affects github.com/mattermost/mattermost-server
GHSA-h998-hxxj-8q83 Mattermost doesn't invalidate cached authentication state for active WebSocket connections during global session revocation	Medium	Also affects github.com/mattermost/mattermost-server
GHSA-g5vr-6pgg-74qv Mattermost doesn't enforce bot-specific permission checks on the user active status endpoint	Low	Also affects github.com/mattermost/mattermost-server
GHSA-jqgv-39mg-7c2r Mattermost doesn't authenticate Atlassian Connect installed callbacks, allowing a remote unauthenticated attacker to inject a rogue sharedSecret	Medium	Also affects github.com/mattermost/mattermost-server
GHSA-mxq2-5jpg-7474 Mattermost doesn't validate channel ownership of an existing subscription before applying edits	Medium	Also affects github.com/mattermost/mattermost-server
GHSA-2g8v-grq3-hq2g Mattermost doesn't enforce administrator authorization on the {{setDefaultInstance}} call within the {{/gitlab connect}} command handler	Medium	Also affects github.com/mattermost/mattermost-server
GHSA-6hxm-w4hv-vgvw Mattermost doesn't require role-management authorization when setting the scheme_admin flag on group syncable link and patch endpoints	High	Also affects github.com/mattermost/mattermost-server
GHSA-9p44-r552-4wp9 Mattermost doesn't sanitize the Remote Cluster API response on PATCH operations	Medium	Also affects github.com/mattermost/mattermost-server

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