CVE-2025-21088
Last modified
CVE-2025-21088 is a medium-severity vulnerability rated 6.5/10 on the CVSS scale. Mattermost versions 10.2.x <= 10.2.0, 9.11.x <= 9.11.5, 10.0.x <= 10.0.3, 10.1.x <= 10.1.3 fail to properly validate the style of proto supplied to an action's style in post.props.attachments, which allows an attacker to crash the frontend via crafted malicious input.. EPSS estimates a 0.54% chance of exploitation in the next 30 days.
Description
Mattermost versions 10.2.x <= 10.2.0, 9.11.x <= 9.11.5, 10.0.x <= 10.0.3, 10.1.x <= 10.1.3 fail to properly validate the style of proto supplied to an action's style in post.props.attachments, which allows an attacker to crash the frontend via crafted malicious input.
Metrics
Weakness Enumeration
Affected Software
| Vendor | Product | Versions |
|---|---|---|
| Mattermost | Mattermost Server | >= 9.11.0, < 9.11.6 |
| Mattermost | Mattermost Server | >= 10.0.0, < 10.0.4 |
| Mattermost | Mattermost Server | >= 10.1.0, < 10.1.4 |
| Mattermost | Mattermost Server | 10.2.0 |
References
- https://mattermost.com/security-updatesVendor Advisory
Timeline
- Published
- Last Modified
- Status
- Analyzed
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How Strix Helps
- How Strix found a critical auth bypass in etcdStrix autonomously discovered a critical authentication bypass in etcd, later designated CVE-2026-33413.
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