CVE-2026-6340 (GCVE-0-2026-6340)
Vulnerability from cvelistv5 – Published: 2026-05-18 07:08 – Updated: 2026-05-18 12:43
VLAI
EPSS
VEX
Title
Memory Exhaustion via Malicious 7zip File Upload
Summary
Mattermost versions 11.5.x <= 11.5.1, 10.11.x <= 10.11.13, 11.4.x <= 11.4.3 fail to validate 7zip archive structure before processing which allows an authenticated attacker to cause server memory exhaustion and denial of service via uploading a specially crafted 7zip file with excessive folder declarations.. Mattermost Advisory ID: MMSA-2026-00573
Severity
4.3 (Medium)
SSVC
Exploitation: none
Automatable: no
Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-05-18 12:43 UTC
CWE
- CWE-789 - Memory Allocation with Excessive Size Value
Assigner
References
1 reference
| URL | Tags |
|---|---|
| https://mattermost.com/security-updates | vendor-advisory |
Impacted products
1 product
| Vendor | Product | Version | CPE status | |
|---|---|---|---|---|
| Mattermost | Mattermost |
Affected:
11.5.0 , ≤ 11.5.1
(semver)
Affected: 10.11.0 , ≤ 10.11.13 (semver) Affected: 11.4.0 , ≤ 11.4.3 (semver) Unaffected: 11.6.0 Unaffected: 11.5.2 Unaffected: 10.11.14 Unaffected: 11.4.4 |
guessed |
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