Project Subscriptions
No advisories yet.
Solution
Update Mattermost to versions 11.5.0, 11.4.1, 11.3.2, 11.2.4, 10.11.12 or higher.
Workaround
No workaround given by the vendor.
| Link | Providers |
|---|---|
| https://mattermost.com/security-updates |
|
Thu, 26 Mar 2026 19:00:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| First Time appeared |
Mattermost mattermost Server
|
|
| CPEs | cpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:* | |
| Vendors & Products |
Mattermost mattermost Server
|
Thu, 26 Mar 2026 14:15:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Metrics |
ssvc
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Thu, 26 Mar 2026 12:00:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| First Time appeared |
Mattermost
Mattermost mattermost |
|
| Vendors & Products |
Mattermost
Mattermost mattermost |
Wed, 25 Mar 2026 16:45:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | Mattermost versions 11.4.x <= 11.4.0, 11.3.x <= 11.3.1, 11.2.x <= 11.2.3, 10.11.x <= 10.11.11 fail to properly validate user identity in the OpenID {{IsSameUser()}} comparison logic, which allows an attacker to take over arbitrary user accounts via an overly permissive substring matching flaw in the user discovery flow.. Mattermost Advisory ID: MMSA-2026-00590 | |
| Title | Account Takeover via Substring Matching in OpenID Connect Authentication | |
| Weaknesses | CWE-303 | |
| References |
| |
| Metrics |
cvssV3_1
|
Projects
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Status: PUBLISHED
Assigner: Mattermost
Published:
Updated: 2026-03-26T13:19:52.338Z
Reserved: 2026-02-23T22:07:32.808Z
Link: CVE-2026-27656
Updated: 2026-03-26T13:19:49.531Z
Status : Analyzed
Published: 2026-03-25T17:16:56.797
Modified: 2026-03-26T18:51:38.050
Link: CVE-2026-27656
No data.
OpenCVE Enrichment
Updated: 2026-03-27T09:30:33Z