CVE-2026-75588Mattermost Desktop App plugin popout scheme validation bypass
Updated under an hour ago ()
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No exploitation reported and no EPSS estimate yet.
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Free account, 1 product
Mattermost Desktop App versions <=6.2 6.2.2.0 fail to validate the URL scheme when checking whether a target URL is internal to the connected server, which allows a network-positioned attacker to load a plugin popout window over an insecure connection via a link using a downgraded URL scheme. Mattermost Advisory ID: MMSA-2026-00717
- CVSS
- 2.6 LOW (v3.1, CNA)CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:U/C:N/I:L/A:N
- Weakness (CWE)
- CWE-1287
- Known exploited
- Not in CISA's KEV catalog
- EPSS (exploitation in the next 30 days)
- Not loaded for this CVE
- Assigned by
- Mattermost
- NVD analysis
- Analyzed
- Record last updated
- Sep 17, 2026
- First seen by InfoSec Signals
- Oct 9, 2026
Affected products
Mattermost Mattermost mattermost:mattermost (from the name) | through 6.2.2; 6.3.0 not affected; 6.2.3.0 not affected | CNA record |
mattermost mattermost_desktop mattermost:mattermost_desktop | from 6.2.0 before 6.2.3 | NVD |
References
- https://mattermost.com/security-updatesvendor-advisory
The CVE record on cve.org NVD's entry
The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.