CVE-2025-9078

Weak cache keys lead to post IDOR and link preview poisoning

Published Sep 15, 2025 CVSS 3.1 · 4.3 Medium EPSS < 1% KEV · Not listed
Description
Mattermost versions 10.8.x <= 10.8.3, 10.5.x <= 10.5.8, 9.11.x <= 9.11.17, 10.10.x <= 10.10.1, 10.9.x <= 10.9.3 fail to properly validate cache keys for link metadata which allows authenticated users to access unauthorized posts and poison link previews via hash collision attacks on FNV-1 hashing

Remediation

Vendor Solution

Update Mattermost to versions 10.11.0, 10.8.4, 10.5.9, 9.11.18, 10.10.2, 10.9.4 or higher.

Tracking

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Advisories

Source ID Title
EUVD EUVD EUVD-2025-29164 Mattermost makes Use of Weak Hash
Github GHSA Github GHSA GHSA-9p92-x77w-9fw2 Mattermost makes Use of Weak Hash
References
History
Type Values Removed Values Added
First Time appeared Mattermost mattermost
Vendors & Products Mattermost mattermost
Type Values Removed Values Added
First Time appeared Mattermost
Mattermost mattermost Server
CPEs cpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:*
Vendors & Products Mattermost
Mattermost mattermost Server
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
Description Mattermost versions 10.8.x <= 10.8.3, 10.5.x <= 10.5.8, 9.11.x <= 9.11.17, 10.10.x <= 10.10.1, 10.9.x <= 10.9.3 fail to properly validate cache keys for link metadata which allows authenticated users to access unauthorized posts and poison link previews via hash collision attacks on FNV-1 hashing
Title Weak cache keys lead to post IDOR and link preview poisoning
Weaknesses CWE-328
References
Metrics cvssV3_1

{'score': 4.3, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
Mattermost
Published
Updated
Sep 15, 2025, 1:57 PM
Reserved
Aug 15, 2025, 3:34 PM
Status
Analyzed
Published
Sep 15, 2025, 10:15 AM
Modified
Oct 19, 2026, 5:10 PM