CVE-2026-1628 json
Mattermost allows external websites to open within the app, exposing preload functionality to non-trusted sites.
published 2026-03-02 8 mo ago modified 2026-06-17 4 mo ago also EUVD-2026-9174
- cvss
- 4.6
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.2%
- EPSS 0.2% chance of exploitation in 30 days, percentile 5%
- public exploits
- 0
- none known
Summary
Mattermost Desktop App versions <=5.13.3 fail to attach listeners restricting navigation to external sites within the Mattermost app which allows a malicious server to expose preload script functionality to untrusted servers via having a user open an external link in their Mattermost server. Mattermost Advisory ID: MMSA-2026-00596
Patch / fix
- Mattermost Mattermost 5.13.4.0
CISA SSVC
- Exploitation
- none
- Automatable
- no
- Technical impact
- partial
- Assessed
- 8 mo ago
Exploit prediction
0.16% chance of exploitation in the next 30 days, higher than 5% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.1 | 4.6 | CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:L/I:L/A:N |
Affected products
- Mattermost Mattermost
Classification
- Weakness
-
- CWE-829 Inclusion of Functionality from Untrusted Control Sphere
References
-
mattermost.com
/security-updates
vendor-advisory
Sources
- CVE List CVE-2026-1628
- NVD CVE-2026-1628
Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.