CVE-2026-28735
Analyzed
Analyzed - Analysis Complete
BaseFortify
Vulnerability report for CVE-2026-28735, including description, CVSS score, EPSS score, affected products, exploitability, helpful resources, and attack-flow context.
Publication date: 2026-05-22
Last updated on: 2026-05-22
Assigner: Mattermost, Inc.
Description
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 validate the OAuth token scope on the callback which allows an authenticated Mattermost user to gain access to private repositories via modifying the scope parameter in the GitHub authorization URL.. Mattermost Advisory ID: MMSA-2026-00628
CVSS Scores
EPSS Scores
| Probability: | |
| Percentile: |
Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| mattermost | mattermost_server | From 10.11.0 (inc) to 10.11.15 (exc) |
| mattermost | mattermost_server | From 11.4.0 (inc) to 11.4.5 (exc) |
| mattermost | mattermost_server | From 11.5.0 (inc) to 11.5.4 (exc) |
| mattermost | mattermost_server | From 11.6.0 (inc) to 11.6.1 (exc) |
Helpful Resources
Exploitability
CWE
KEV
| CWE ID | Description |
|---|---|
| CWE-863 | The product performs an authorization check when an actor attempts to access a resource or perform an action, but it does not correctly perform the check. |
