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OpenAdvisories
High · 8.7 CVE-2026-6346 EUVD-2026-30754GHSA-9p64-jpc7-m2rpGO-2026-5293

Sensitive credentials exposed in plaintext in Mattermost support packets

Published May 18, 2026 · Updated May 18, 2026 · Assigned by Mattermost

Description

Mattermost versions 11.5.x <= 11.5.1, 10.11.x <= 10.11.13, 11.4.x <= 11.4.3 fail to sanitize sensitive configuration fields before including them in support packet generation, which allows a Mattermost System Admin or any party with access to a support packet to obtain sensitive credentials in plaintext via downloading a support packet from the System Console.. Mattermost Advisory ID: MMSA-2026-00607

Affected products

VendorProductAffectedFixed
Mattermost Mattermost 11.5.0 – ≤ 11.5.1, 10.11.0 – ≤ 10.11.13, 11.4.0 – ≤ 11.4.3 11.6.0

Fixed in Linux distributions

Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.

ReleasePackageFixed inAdvisory
openSUSE Leap 16.0 govulncheck-vulndb 0.0.20260723T184607-160000.1.1 openSUSE-SU-2026:21483-1

Affected packages

EcosystemPackageAffectedFixedRecord
Go github.com/mattermost/mattermost-server < 5.3.2-0.20260326202606-fac92f4a71f3 5.3.2-0.20260326202606-fac92f4a71f3 GHSA-9p64-jpc7-m2rp
Go github.com/mattermost/mattermost-server >= 10.11.0+incompatible, < 10.11.14+incompatible · >= 11.4.0+incompatible, < 11.4.4+incompatible · >= 11.5.0+incompatible, < 11.5.2+incompatible 10.11.14+incompatible, 11.4.4+incompatible, 11.5.2+incompatible GO-2026-5293
Go github.com/mattermost/mattermost-server/v5 all versions — GO-2026-5293
Go github.com/mattermost/mattermost-server/v6 all versions — GO-2026-5293
Go github.com/mattermost/mattermost/server/v8 >= 11.5.0, < 11.5.2 11.5.2 GHSA-9p64-jpc7-m2rp
Go github.com/mattermost/mattermost/server/v8 >= 10.11.0, < 10.11.14 10.11.14 GHSA-9p64-jpc7-m2rp
Go github.com/mattermost/mattermost/server/v8 >= 11.4.0, < 11.4.4 11.4.4 GHSA-9p64-jpc7-m2rp
Go github.com/mattermost/mattermost/server/v8 < 8.0.0-20260326202606-fac92f4a71f3 8.0.0-20260326202606-fac92f4a71f3 GHSA-9p64-jpc7-m2rp

Advisories 1

References