CVE-2026-4915
6.5
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Summary
Mattermost versions 11.6.x <= 11.6.0, 11.5.x <= 11.5.3, 11.4.x <= 11.4.4, 10.11.x <= 10.11.14 fail to filter nil elements from outgoing webhook attachment payloads before processing, which allows an authenticated user to cause a denial of service (server process termination) via a crafted webhook callback response containing a null attachment entry.. Mattermost Advisory ID: MMSA-2026-00641
Affected Software
| Vendor | Product | Version Range | Status |
|---|---|---|---|
| Mattermost | Mattermost | 11.6.0 <= 11.6.0 | affected |
| Mattermost | Mattermost | 11.5.0 <= 11.5.3 | affected |
| Mattermost | Mattermost | 11.4.0 <= 11.4.4 | affected |
| Mattermost | Mattermost | 10.11.0 <= 10.11.14 | affected |
| Mattermost | Mattermost | 11.7.0 | unaffected |
| Mattermost | Mattermost | 11.6.1 | unaffected |
| Mattermost | Mattermost | 11.5.4 | unaffected |
| Mattermost | Mattermost | 11.4.5 | unaffected |
| Mattermost | Mattermost | 10.11.15 | unaffected |
Weaknesses
- CWE-754: CWE-754: Improper Check for Unusual or Exceptional Conditions
ADP Enrichment
CISA ADP Vulnrichment
- SSVC:
- Exploitation: none
- Automatable: no
- Technical Impact: partial
References
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