CVE-2026-5308
Low
No strong exploitation signal.
CVSS base
4.9
MEDIUM
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H
EPSS — probability of exploitation (30 days)
0.3%
17.3th percentile
CISA KEV
Not listed
Weakness / dates
CWE-400
Published 2026-05-22 · modified 2026-07-23
CVSS breakdown
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H
| Attack Vector | N | Network |
| Attack Complexity | L | Low |
| Privileges Required | H | High |
| User Interaction | N | None |
| Scope | U | Unchanged |
| Confidentiality | N | None |
| Integrity | N | None |
| Availability | H | High |
Timeline
- 2026-05-22 — Published (NVD)
- 2026-07-23 — Last modified (NVD)
Description
Mattermost versions 11.6.x <= 11.6.0, 11.5.x <= 11.5.3, 11.4.x <= 11.4.4, 10.11.x <= 10.11.14 fail to enforce request body size limits on plugin HTTP endpoints which allows an attacker to cause a denial of service via crafted oversized HTTP requests.. Mattermost Advisory ID: MMSA-2026-00646