Vulnerability · Published Sep 15, 2025 · Assigned by Mattermost
CVE-2025-9078Weak cache keys lead to post IDOR and link preview poisoning
Medium 4.3
In plain English
A medium-severity security flaw in Mattermost from Mattermost. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 5% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Severity (CVSS 3.1)4.3Medium
Exploit odds (30 days)0.2%top 95.4% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known
Official 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
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Go | github.com/mattermost/mattermost-server | 10.10.2+incompatible, 10.5.9+incompatible, 10.8.4+incompatible, 10.9.4+incompatible, 9.11.18+incompatible | GO-2025-3959 |
| Go | github.com/mattermost/mattermost-server | 10.8.4 | GHSA-9p92-x77w-9fw2 |
| Go | github.com/mattermost/mattermost-server | 9.11.18 | GHSA-9p92-x77w-9fw2 |
| Go | github.com/mattermost/mattermost-server | 10.10.2 | GHSA-9p92-x77w-9fw2 |
| Go | github.com/mattermost/mattermost-server | 10.9.4 | GHSA-9p92-x77w-9fw2 |
| Go | github.com/mattermost/mattermost-server | 10.5.9 | GHSA-9p92-x77w-9fw2 |
| Go | github.com/mattermost/mattermost-server/v5 | no fix listed | GO-2025-3959 |
| Go | github.com/mattermost/mattermost-server/v6 | no fix listed | GO-2025-3959 |
| Go | github.com/mattermost/mattermost/server/v8 | 8.0.0-20250718075842-cd87e5c87737 | GO-2025-3959 |
| Go | github.com/mattermost/mattermost/server/v8 | 8.0.0-20250718075842-cd87e5c87737 | GHSA-9p92-x77w-9fw2 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| Mattermost | Mattermost | 10.8.0 – through 10.8.310.5.0 – through 10.5.89.11.0 – through 9.11.1710.10.0 – through 10.10.110.9.0 – through 10.9.3 |
Weakness: CWE-328 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N