System Role with manage posts permission can read posts of Direct Messages

published 2023-09-29 3 y ago modified 2026-06-17 4 mo ago also GHSA-h8wh-f7gw-fwpr , EUVD-2023-2520

cvss: 4.9; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.6%; EPSS 0.6% chance of exploitation in 30 days, percentile 47%
public exploits: 0; none known

Mattermost fails to properly check permissions when retrieving a post allowing for a System Role with the permission to manage channels to read the posts of a DM conversation.

Patch / fix

fixed in 3

go github.com/mattermost/mattermost/server/v8 8.0.2, 8.1.1
go github.com/mattermost/mattermost-server/v6 7.8.10
Mattermost Mattermost 7.8.10, 8.0.2, 8.1.1

CISA SSVC

Exploitation: none
Automatable: no
Technical impact: partial
Assessed: 2 y ago (2024-09-20)

Exploit prediction

0.57% chance of exploitation in the next 30 days, higher than 47% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
CNA	3.1	4.9	CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:N/A:N
NVD	3.1	2.7	CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:L/I:N/A:N
GitHub	3.1	2.7	CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:L/I:N/A:N

Affected packages

ecosystem	package	affected	fixed in
go	github.com/mattermost/mattermost/server/v8	>=8.1.0, <8.1.1 >=8.0.0, <8.0.2	8.1.1 8.0.2
go	github.com/mattermost/mattermost-server/v6	<7.8.10	7.8.10

Affected products

Mattermost Mattermost

Classification

Weakness

CWE-863 Incorrect Authorization

References

mattermost.com /security-updates
web, vendor-advisory
nvd.nist.gov /vuln/detail/CVE-2023-5193
advisory
github.com /mattermost/mattermost
package

Sources

CVE List CVE-2023-5193
GitHub Advisory GHSA-h8wh-f7gw-fwpr
NVD CVE-2023-5193

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