Medium severity · published Jul 27, 2026
CVE-2026-10600
Denial of service via unbounded document content extraction in Mattermost Server
4.3
CVSS
0.4%
EPSS
No
On KEV
Description
Mattermost versions 11.8.x <= 11.8.0, 11.7.x <= 11.7.3, 11.6.x <= 11.6.5, 10.11.x <= 10.11.20 fail to bound the time and resource consumption of server-side document content extraction which allows an authenticated user with file-upload permission to degrade file uploads for all users on the server via repeatedly uploading small documents that are cheap to upload but expensive to extract, saturating the shared extraction worker pool.. Mattermost Advisory ID: MMSA-2026-00694
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
None
Confidentiality
None
Integrity
None
Availability
Low
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.4% · higher than 30% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
MA
Mattermost · Mattermost
11.8.0 through 11.8.0; 11.7.0 through 11.7.3; 11.6.0 through 11.6.5; 10.11.0 through 10.11.20 · source: vendor
MS
Mattermost Server · Mattermost
10.11.0 before 10.11.21; 11.6.0 before 11.6.6; 11.7.0 before 11.7.4; 11.8.0 before 11.8.1 · source: NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-10600
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-10600
Vendor Advisory
https://mattermost.com/security-updates
More from Mattermost
9.9
CVE-2026-4858
Path traversal in integration action URL leading to arbitrary API execution via system admin’s auth token.
9.9
CVE-2025-12421
Account Takeover via Code Exchange Endpoint
9.9
CVE-2025-12419
Account takeover on OAuth/OpenID-enabled servers
9.9
CVE-2025-4981
Path Traversal Leading to RCE by Any Authenticated Mattermost User
9.6
CVE-2024-39777
Mattermost versions 9.9.x <= 9.9.0, 9.5.x <= 9.5.6, 9.7.x <= 9.7.5 and 9.8.x <= 9.8.1 fail to disallow unsolicited invites to expose access to local channels, when shared channels…