What is CVE-2023-2783?

CVE-2023-2783 is a medium-severity vulnerability in Mattermost, classified under Missing Authorization. CVSS score: 4.3/10. Published 2023-06-16.

How severe is CVE-2023-2783?

Medium severity. CVSS v3 base score is 4.3 out of 10.

Auth bypass in Mattermost

CVE-2023-2783

Mattermost Apps Framework fails to verify that a secret provided in the incoming webhook request allowing an attacker to modify the contents of the post sent by the Apps.

Vulnerability class: Broken Access Control

Published 2023-06-16 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 4.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N.

EPSS exploit prediction

EPSS: 0.004 (35.6th percentile), scored 2026-09-30.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 36th percentile — 35.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.004 · newest: 0.004 · change: 0.000

Affected products

Mattermost — versions 7.10.0
Mattermost App Framework — versions 0, 7.10.0, 7.10.1

Weakness classification (CWE)

CWE-862 — Missing Authorization

References

mattermost.com/security-updates (Vendor Advisory)

Frequently asked questions

What is CVE-2023-2783?: CVE-2023-2783 is a medium-severity vulnerability in Mattermost, classified under Missing Authorization. CVSS score: 4.3/10. Published 2023-06-16.
How severe is CVE-2023-2783?: Medium severity. CVSS v3 base score is 4.3 out of 10.