Mattermost has Potential Server Crash due to Unvalidated Import Data

CVE-2025-8402 → View on GitHub ↗ View on CVE.org ↗ View on NVD ↗

Description

Mattermost versions 10.8.x <= 10.8.3, 10.5.x <= 10.5.8, 9.11.x <= 9.11.17, 10.10.x <= 10.10.0, 10.9.x <= 10.9.3 fail to validate import data which allows a system admin to crash the server via the bulk import feature.

Basic information

Type
reviewed
Severity
medium
Advisory on GitHub
Open advisory ↗
Repository advisory
—
Source code
Browse source ↗
Published (advisory)
2025-08-21 18:31:29 UTC
Updated
2025-08-29 21:02:13 UTC
GitHub reviewed
2025-08-22 17:34:35 UTC
NVD published
2025-08-21

EPSS Score

Score Percentile
0.11% 29.14%

CVSS Scores

Base score Version Severity Vector
4.9 3.1 —
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:H)
They need powerful rights—admin, root, or similar—before this pays off.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.

Identifiers

Type Value
GHSA GHSA-h469-4fcf-p23h ↗
CVE CVE-2025-8402 ↗

CWEs

CWE id Name
CWE-476 NULL Pointer Dereference

Affected packages (8)

Vulnerable version ranges and first patched releases as published by GitHub.

Ecosystem Package Vulnerable range First patched Vulnerable functions
go github.com/mattermost/mattermost-server >= 10.8.0, <= 10.8.3 10.8.4 —
go github.com/mattermost/mattermost-server >= 10.5.0, <= 10.5.8 10.5.9 —
go github.com/mattermost/mattermost-server >= 10.9.0, <= 10.9.3 10.9.4 —
go github.com/mattermost/mattermost-server = 10.10.0 10.10.1 —
go github.com/mattermost/mattermost/server/v8 < 8.0.0-20250708173752-d6b35c41f0ae5 8.0.0-20250708173752-d6b35c41f0ae5 —
go github.com/mattermost/mattermost-server >= 9.11.0, <= 9.11.17 9.11.18 —
go github.com/mattermost/mattermost-server/v5 <= 5.39.3 — —
go github.com/mattermost/mattermost-server/v6 <= 6.7.2 — —

References

cvelogic Threat Intelligence