CVE-2025-8402 | Nil pointer dereference in bulk import crashes server

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.

Published: 2025-08-21 Last update: 2025-10-01 Assigner: [email protected] Source: [email protected]
NVD Status：Analyzed，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2025-8402 is rated Low Risk (31.7/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.15%). Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2025-8402

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-07 0.15% 0.15% -0.01%
2 2026-05-17 0.06% 0.15% +0.09%
3 2025-08-22 — 0.06% —

Full EPSS history (3 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2025-8402

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
4.9 3.1 MEDIUM
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.
 1.2 3.6 [email protected]

Weakness enumeration for CVE-2025-8402

GitHub Security Advisory for CVE-2025-8402

GHSA-h469-4fcf-p23h · Severity: medium · Ecosystem: go — Mattermost has Potential Server Crash due to Unvalidated Import Data

Affected software / configurations for CVE-2025-8402

Vendor Product Version Raw CPE
mattermost mattermost_server >= 9.11.0, < 9.11.18 cpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:*
mattermost mattermost_server >= 10.5.0, < 10.5.9 cpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:*
mattermost mattermost_server >= 10.8.0, < 10.8.4 cpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:*
mattermost mattermost_server >= 10.9.0, < 10.9.4 cpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:*
mattermost mattermost_server 10.10.0 cpe:2.3:a:mattermost:mattermost_server:10.10.0:-:*:*:*:*:*:*

References for CVE-2025-8402

URL Tags
https://mattermost.com/security-updates Vendor Advisory
cvelogic Threat Intelligence