Mattermost makes Use of Weak Hash

CVE-2025-9078 → View on GitHub ↗ View on CVE.org ↗ View on NVD ↗

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.

Basic information

Type
reviewed
Severity
medium
Advisory on GitHub
Open advisory ↗
Repository advisory
—
Source code
Browse source ↗
Published (advisory)
2025-09-15 12:31:25 UTC
Updated
2025-09-16 19:13:12 UTC
GitHub reviewed
2025-09-16 19:13:08 UTC
NVD published
2025-09-15 10:15:32 UTC

EPSS Score

Score Percentile
0.02% 6.15%

CVSS Scores

Base score Version Severity Vector
4.3 3.1 —
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:L)
Some sensitive info could get out, but not a total data dump.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:N)
Service keeps running; no real outage angle.

Identifiers

Type Value
GHSA GHSA-9p92-x77w-9fw2 ↗
CVE CVE-2025-9078 ↗

CWEs

CWE id Name
CWE-328 Use of Weak Hash

Affected packages (6)

Vulnerable version ranges and first patched releases as published by GitHub.

Ecosystem Package Vulnerable range First patched Vulnerable functions
go github.com/mattermost/mattermost-server >= 10.8.0, < 10.8.4 10.8.4 —
go github.com/mattermost/mattermost-server >= 10.5.0, < 10.5.9 10.5.9 —
go github.com/mattermost/mattermost-server >= 9.11.0, < 9.11.18 9.11.18 —
go github.com/mattermost/mattermost-server >= 10.10.0, < 10.10.2 10.10.2 —
go github.com/mattermost/mattermost-server >= 10.9.0, < 10.9.4 10.9.4 —
go github.com/mattermost/mattermost/server/v8 < 8.0.0-20250718075842-cd87e5c87737 8.0.0-20250718075842-cd87e5c87737 —

References

cvelogic Threat Intelligence