CVE-2026-3114
Zip Bomb Denial of Service in Mattermost File Extraction
Publication date: 2026-03-26
Last updated on: 2026-03-30
Assigner: Mattermost, Inc.
Description
Description
CVSS Scores
EPSS Scores
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Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| mattermost | mattermost_server | From 10.11.0 (inc) to 10.11.12 (exc) |
| mattermost | mattermost_server | From 11.2.0 (inc) to 11.2.4 (exc) |
| mattermost | mattermost_server | From 11.3.0 (inc) to 11.3.2 (exc) |
| mattermost | mattermost_server | 11.4.0 |
Helpful Resources
Exploitability
| CWE ID | Description |
|---|---|
| CWE-409 | The product does not handle or incorrectly handles a compressed input with a very high compression ratio that produces a large output. |
Attack-Flow Graph
AI Powered Q&A
Can you explain this vulnerability to me?
This vulnerability exists in certain versions of Mattermost (11.4.x <= 11.4.0, 11.3.x <= 11.3.1, 11.2.x <= 11.2.3, 10.11.x <= 10.11.11) where the software fails to validate the decompressed sizes of archive entries during file extraction.
Because of this, authenticated users who have file upload permissions can upload specially crafted zip archives containing highly compressed entries, known as zip bombs.
These zip bombs cause the server to exhaust its memory resources during extraction, leading to a denial of service condition.
How can this vulnerability impact me? :
The primary impact of this vulnerability is a denial of service (DoS) on the Mattermost server.
An attacker who is authenticated and has permission to upload files can exploit this by uploading a crafted zip archive that consumes excessive server memory during extraction.
This can cause the server to become unresponsive or crash, disrupting normal operations and availability of the Mattermost service.