CVE-2026-6517
published 2026-06-15CVE-2026-6517: Mattermost Desktop App versions <=6.1 5.5.13.0 fail to restrict the allow list of domains to which NTLM credentials were forwarded to in the Mattermost Desktop…
PriorityP346high7.7CVSS 3.1
AVNACLPRLUINSCCHINAN
EPSS
0.19%
8.5th percentile
Mattermost Desktop App versions <=6.1 5.5.13.0 fail to restrict the allow list of domains to which NTLM credentials were forwarded to in the Mattermost Desktop App which allows any user on a server without the image proxy enabled to intercept other users credentials via embedding an image that routes to an external web server. Mattermost Advisory ID: MMSA-2026-00651
Affected
3 ranges
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| mattermost | mattermost | <= 5.5.13 | — |
| mattermost | mattermost_desktop | <= 5.13.0 | — |
| mattermost | mattermost_desktop | 6.1.0 – 6.1.5 | — |
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GHSA
Mattermost Desktop App versions <=6.1 5.5.13.0 fail to restrict the allow list of domains to which NTLM credentials were forwarded to in the Mattermost Desktop App which allows any user on a server wi
ghsa_unreviewed·2026-06-15
CVE-2026-6517 [MEDIUM] CWE-522 Mattermost Desktop App versions <=6.1 5.5.13.0 fail to restrict the allow list of domains to which NTLM credentials were forwarded to in the Mattermost Desktop App which allows any user on a server wi
Mattermost Desktop App versions <=6.1 5.5.13.0 fail to restrict the allow list of domains to which NTLM credentials were forwarded to in the Mattermost Desktop App which allows any user on a server without the image proxy enabled to intercept other users credentials via embedding an image that routes to an external web server. Mattermost Advisory ID: MMSA-2026-00651
VulDB
Mattermost Desktop App up to 5.5.13/6.1.x insufficiently protected credentials
vuldb·2026-06-15·CVSS 6.3
CVE-2026-6517 [MEDIUM] Mattermost Desktop App up to 5.5.13/6.1.x insufficiently protected credentials
A vulnerability was found in Mattermost Desktop App up to 5.5.13/6.1.x. It has been classified as problematic. Affected by this issue is some unknown functionality. This manipulation causes insufficiently protected credentials.
This vulnerability is handled as CVE-2026-6517. The attack can be initiated remotely. There is not any exploit available.
Upgrading the affected component is recommended.
No detection rules found.
No public exploits indexed.
No writeups or analysis indexed.
2026-06-15
Published