UpHeron
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Servers and applications

CVE-2026-93848

Mattermost OpenID discovery endpoint request bypasses outbound connection filtering, allowing SSRF by a System Administrator

Severity
Low 2.7
Published
26 Oct 2026
Last changed
2 Nov 2026
Added to UpHeron
3 Nov 2026
Fixed in
11.7.11
Sources
NVD, CVE Program

Description

Mattermost versions 11.7.x <= 11.7.10 fail to apply outbound internal-connection filtering to the OpenID discovery endpoint request which allows a System Administrator to determine whether internal addresses and ports are reachable from the server via an unauthenticated login request that triggers the discovery fetch.. Mattermost Advisory ID: MMSA-2026-00774

Affected software

SoftwareAffected versions
MattermostServers and applications · cna:mattermost|mattermost
  • From 11.7.0 up to 11.7.10
MattermostServers and applications · cpe:a:mattermost:mattermost_server
  • From 11.7.0 before 11.7.11

References

  • NVD https://nvd.nist.gov/vuln/detail/CVE-2026-93848
  • CVE.org https://www.cve.org/CVERecord?id=CVE-2026-93848