CVE-2025-6227 | Invite token is used as part of the secure communication

Mattermost versions 10.5.x <= 10.5.7, 9.11.x <= 9.11.16 fail to negotiate a new token when accepting the invite which allows a user that intercepts both invite and password to send synchronization payloads to the server that originally created the invite via the REST API.

Published: 2025-07-18 Last update: 2025-10-14 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2025-6227 is rated Low Risk (20.7/100): CVSS Low severity, with low exploitation likelihood (EPSS 0.14%). Mandatory action: 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-2025-6227

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 2026-05-14 0.03% 0.14% +0.11%
2 2025-07-18 0.03%

Full EPSS history (2 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2025-6227

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
2.2 3.1 LOW
CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:N/I:L/A:N 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:H)
Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
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:L)
Attackers could change some data, but it’s limited—not everything goes.
Availability (A:N)
Service keeps running; no real outage angle.
0.7 1.4 [email protected]
3.1 3.1 LOW
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:L/A:N 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:H)
Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
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:L)
Attackers could change some data, but it’s limited—not everything goes.
Availability (A:N)
Service keeps running; no real outage angle.
1.6 1.4 [email protected]

Weakness enumeration for CVE-2025-6227

GitHub Security Advisory for CVE-2025-6227

GHSA-4fwj-8595-wp25 · Severity: low · Ecosystem: go — Mattermost has Insufficiently Protected Credentials

Affected software / configurations for CVE-2025-6227

Vendor Product Version Raw CPE
mattermost mattermost_server >= 9.11.0, < 9.11.17 cpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:*
mattermost mattermost_server >= 10.5.0, < 10.5.8 cpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:*

References for CVE-2025-6227

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