CVE-2025-8285 | Unauthorized Channel Subscription Creation in Mattermost Confluence Plugin

Mattermost Confluence Plugin version <1.5.0 fails to check the access of the user to the channel which allows attackers to create channel subscription without proper access to the channel via API call to the create channel subscription endpoint.

Published: 2025-08-11 Last update: 2026-06-17 Assigner: [email protected] Source: [email protected]
NVD Status：Analyzed，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2025-8285 is rated Low Risk (31.3/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.21%). 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-2025-8285

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 0.05% 0.21% +0.16%
2 2026-04-27 0.03% 0.05% +0.02%
3 2026-01-07 — 0.03% —

Full EPSS history (5 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2025-8285

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
4.0 3.1 MEDIUM
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/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:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:C)
Breaking this can reach past the original component and bite other resources—bigger blast radius.
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.
 2.2 1.4 [email protected]
5.3 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:N/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:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
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.
 3.9 1.4 [email protected]

Weakness enumeration for CVE-2025-8285

GitHub Security Advisory for CVE-2025-8285

GHSA-qjrx-j8wm-xf83 · Severity: medium · Ecosystem: go — Mattermost Confluence Plugin has Missing Authorization vulnerability

Affected software / configurations for CVE-2025-8285

Vendor Product Version Raw CPE
mattermost confluence < 1.5.0 cpe:2.3:a:mattermost:confluence:*:*:*:*:*:*:*:*

References for CVE-2025-8285

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