Mattermost versions 11.8.x <= 11.8.2, 11.7.x <= 11.7.6, 10.11.x <= 10.11.21 fail to restrict channel member role assignment to channel-scoped roles… (CVE-2026-16048)
Mattermost versions 11.8.x up to 11.8.2, 11.7.x up to 11.7.6, and 10.11.x up to 10.11.21 contain a vulnerability where channel member role assignment is not properly restricted to channel-scoped roles. This flaw allows a channel administrator to escalate their permissions by using the channel member roles API to gain additional channel permissions beyond intended limits.
AI Analysis
Technical Summary
CVE-2026-16048 affects Mattermost versions 11.8.x <= 11.8.2, 11.7.x <= 11.7.6, and 10.11.x <= 10.11.21. The vulnerability arises because the software fails to restrict channel member role assignments strictly to channel-scoped roles. As a result, a channel administrator can exploit the channel member roles API to escalate their permissions within a channel, potentially gaining unauthorized capabilities. The issue is classified under CWE-863 (Incorrect Authorization). The CVSS 3.1 base score is 6.3, indicating a moderate severity level with network attack vector, low attack complexity, requiring privileges, no user interaction, and impacts on confidentiality, integrity, and availability.
Potential Impact
An attacker with channel administrator privileges can escalate their permissions within the channel beyond what is intended by exploiting the channel member roles API. This can lead to unauthorized access or modification of channel content and potentially disrupt channel operations. The impact affects confidentiality, integrity, and availability of channel data but requires existing channel admin privileges.
Mitigation Recommendations
No explicit patch or remediation details are provided in the available data. Patch status is not yet confirmed — check the Mattermost vendor advisory MMSA-2026-00697 for current remediation guidance. Until a fix is applied, restrict channel administrator privileges carefully and monitor for unauthorized role changes. Follow vendor instructions once a patch or update is released.
Mattermost versions 11.8.x <= 11.8.2, 11.7.x <= 11.7.6, 10.11.x <= 10.11.21 fail to restrict channel member role assignment to channel-scoped roles… (CVE-2026-16048)
Description
Mattermost versions 11.8.x up to 11.8.2, 11.7.x up to 11.7.6, and 10.11.x up to 10.11.21 contain a vulnerability where channel member role assignment is not properly restricted to channel-scoped roles. This flaw allows a channel administrator to escalate their permissions by using the channel member roles API to gain additional channel permissions beyond intended limits.
CVSS v3.1
Score 6.3medium
Affected software
pkg:github/mattermost/mattermost-serverRun on your own infrastructure? Check whether these packages are installed with threat-finder — our free open-source scanner.
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
CVE-2026-16048 affects Mattermost versions 11.8.x <= 11.8.2, 11.7.x <= 11.7.6, and 10.11.x <= 10.11.21. The vulnerability arises because the software fails to restrict channel member role assignments strictly to channel-scoped roles. As a result, a channel administrator can exploit the channel member roles API to escalate their permissions within a channel, potentially gaining unauthorized capabilities. The issue is classified under CWE-863 (Incorrect Authorization). The CVSS 3.1 base score is 6.3, indicating a moderate severity level with network attack vector, low attack complexity, requiring privileges, no user interaction, and impacts on confidentiality, integrity, and availability.
Potential Impact
An attacker with channel administrator privileges can escalate their permissions within the channel beyond what is intended by exploiting the channel member roles API. This can lead to unauthorized access or modification of channel content and potentially disrupt channel operations. The impact affects confidentiality, integrity, and availability of channel data but requires existing channel admin privileges.
Mitigation Recommendations
No explicit patch or remediation details are provided in the available data. Patch status is not yet confirmed — check the Mattermost vendor advisory MMSA-2026-00697 for current remediation guidance. Until a fix is applied, restrict channel administrator privileges carefully and monitor for unauthorized role changes. Follow vendor instructions once a patch or update is released.
Technical Details
- Gcve Source
- db.gcve.eu
- Osv Id
- GHSA-v37p-g38w-w7wg
- Osv Schema Version
- 1.4.0
- Aliases
- ["CVE-2026-16048"]
- Ecosystems
- []
- Database Specific Severity
- MODERATE
- Cvss Version
- 3.1
Threat ID: 6a833342bf8831d5392a3a87
Added to database: 08/17/2026, 16:13:54 UTC
Last enriched: 08/17/2026, 16:15:08 UTC
Last updated: 08/17/2026, 19:21:05 UTC
Views: 2
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