Unauthorized channel member management through playbook runs

published 2025-06-20 16 mo ago modified 2026-06-17 4 mo ago also GHSA-qwwm-c582-82rx , GO-2025-3772 , EUVD-2025-18758

cvss: 4.3; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.2%; EPSS 0.2% chance of exploitation in 30 days, percentile 15%
public exploits: 0; none known

Mattermost versions 10.5.x <= 10.5.5, 9.11.x <= 9.11.15, 10.8.x <= 10.8.0, 10.7.x <= 10.7.2, 10.6.x <= 10.6.5 fail to properly enforce channel member management permissions in playbook runs, allowing authenticated users without the 'Manage Channel Members' permission to add or remove users from public and private channels by manipulating playbook run participants when the run is linked to a channel.

Patch / fix

fixed in 3 distros 1

go github.com/mattermost/mattermost-server 0.0.0-20250520060012-d0380305ef7a, 9.11.16+incompatible, 10.5.6+incompatible, 10.6.6+incompatible, 10.7.3+incompatible, 10.8.1+incompatible
go github.com/mattermost/mattermost/server/v8 8.0.0-20250520060012-d0380305ef7a, 9.11.16, 10.5.6, 10.6.6, 10.7.3, 10.8.1
Mattermost Mattermost 9.11.16, 10.5.6, 10.6.6, 10.7.3, 10.8.1, 10.9.0

govulncheck-vulndb openSUSE Tumbleweed 0.0.20250730T213748-1.1

opensuse advisories openSUSE-SU-2025:15405-1

CISA SSVC

Exploitation: none
Automatable: no
Technical impact: partial
Assessed: 16 mo ago (2025-06-23)

Exploit prediction

0.25% chance of exploitation in the next 30 days, higher than 15% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
CNA	3.1	4.3	CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N
NVD	3.1	4.3	CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N
GitHub	3.1	4.3	CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N

Affected packages

ecosystem	package	affected	fixed in
go	github.com/mattermost/mattermost-server	<0.0.0-20250520060012-d0380305ef7a >=9.11.0+incompatible, <9.11.16+incompatible >=10.5.0+incompatible, <10.5.6+incompatible >=10.6.0+incompatible, <10.6.6+incompatible >=10.7.0+incompatible, <10.7.3+incompatible >=10.8.0+incompatible, <10.8.1+incompatible	0.0.0-20250520060012-d0380305ef7a 9.11.16+incompatible 10.5.6+incompatible 10.6.6+incompatible 10.7.3+incompatible 10.8.1+incompatible
go	github.com/mattermost/mattermost/server/v8	<8.0.0-20250520060012-d0380305ef7a >=10.5.0, <10.5.6 >=9.11.0, <9.11.16 >=10.8.0, <10.8.1 >=10.7.0, <10.7.3 >=10.6.0, <10.6.6	8.0.0-20250520060012-d0380305ef7a 10.5.6 9.11.16 10.8.1 10.7.3 10.6.6
go	github.com/mattermost/mattermost-server/v5	all versions	no fix listed
go	github.com/mattermost/mattermost-server/v6	all versions	no fix listed

Affected products

Mattermost Mattermost

Classification

Weakness

CWE-863 Incorrect Authorization

References

mattermost.com /security-updates
web, vendor-advisory
nvd.nist.gov /vuln/detail/CVE-2025-3227
advisory
github.com /mattermost/mattermost
package
github.com /advisories/GHSA-qwwm-c582-82rx
advisory

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary