Mattermost Playbooks exposes private channel metadata to unauthorized users via run metadata API

published 2025-06-30 16 mo ago modified 2026-06-17 4 mo ago also GHSA-wgvp-jj4w-88hf , GO-2025-3797 , EUVD-2025-19558

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 10%
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 validate channel membership when retrieving playbook run metadata, allowing authenticated users who are playbook members but not channel members to access sensitive information about linked private channels including channel name, display name, and participant count through the run metadata API endpoint.

Patch / fix

fixed in 3 distros 1

go github.com/mattermost/mattermost-server 0.0.0-20250513065225-4ae5d647fb88, 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 8.0.0-20250513065225-4ae5d647fb88, 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 (2025-06-30)

Exploit prediction

0.20% chance of exploitation in the next 30 days, higher than 10% 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:N/I:L/A:N
NVD	3.1	5.4	CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N
GitHub	3.1	4.3	CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N

Affected packages

ecosystem	package	affected	fixed in
go	github.com/mattermost/mattermost-server	<0.0.0-20250513065225-4ae5d647fb88 >=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	0.0.0-20250513065225-4ae5d647fb88 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	<8.0.0-20250513065225-4ae5d647fb88 >=9.11.0, <9.11.16 >=10.5.0, <10.5.6 >=10.6.0, <10.6.6 >=10.7.0, <10.7.3 >=10.8.0, <10.8.1	8.0.0-20250513065225-4ae5d647fb88 9.11.16 10.5.6 10.6.6 10.7.3 10.8.1
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-2025-47871
advisory
github.com /mattermost/mattermost
package
github.com /advisories/GHSA-wgvp-jj4w-88hf
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