CVE-2026-6046
5.3
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N
Summary
Mattermost versions 11.6.x <= 11.6.1, 11.5.x <= 11.5.4, 10.11.x <= 10.11.15, 10.11.x <= 10.11.16 fail to validate that a username returned during bot registration belongs to a bot account, which allows an unprivileged attacker to intercept private messages sent by plugins via direct message channels by pre-registering a user account with a predictable plugin bot username.. Mattermost Advisory ID: MMSA-2026-00649
Affected Software
| Vendor | Product | Version Range | Status |
|---|---|---|---|
| Mattermost | Mattermost | 11.6.0 <= 11.6.1 | affected |
| Mattermost | Mattermost | 11.5.0 <= 11.5.4 | affected |
| Mattermost | Mattermost | 10.11.0 <= 10.11.15 | affected |
| Mattermost | Mattermost | 10.11.0 <= 10.11.16 | affected |
| Mattermost | Mattermost | 11.7.0 | unaffected |
| Mattermost | Mattermost | 11.6.2 | unaffected |
| Mattermost | Mattermost | 11.5.5 | unaffected |
| Mattermost | Mattermost | 10.11.16 | unaffected |
| Mattermost | Mattermost | 10.11.17 | unaffected |
Weaknesses
- CWE-200: CWE-200 Exposure of Sensitive Information to an Unauthorized Actor
ADP Enrichment
CISA ADP Vulnrichment
- SSVC:
- Exploitation: none
- Automatable: no
- Technical Impact: partial
References
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