Vulnerability in Mattermost Desktop App (CVE-2026-75588)
Summary
Vulnerability in Mattermost Desktop App (CVE-2026-75588). Risk of unauthorized operations or information disclosure.
Original description
The description as published by the source.
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
Source: NIST National Vulnerability Database NVD GitHub Advisory
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2026-75588 has been found in Mattermost Desktop App.
Risk of unauthorized operations or information disclosure. CVSS score: 2.6/10.
What to do: apply the vendor's official patched release.
If unsure, ask your IT team or search "Mattermost Desktop App CVE-2026-75588" on the vendor's site.
CVE-2026-75588 (Mattermost Desktop App) — CWE-1287 / CVSS v3 2.6
Attack vector: remote (network-reachable)
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
A vulnerability (CWE-1287) exists in Mattermost Desktop App.
Check the vendor advisory for the affected versions of Mattermost Desktop App.
Severity: Low (CVSS 2.6/10). Risk of unauthorized operations or information disclosure.
Update to the patched release per vendor advisory.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Audit SBOM/dependencies to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
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1Identify exposure identify
Audit SBOM/dependencies for affected components.資産台帳・SBOM・依存マニフェストで Mattermost Desktop App を使っているサービスとバージョンを洗い出す。
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2Post-deployment verification verify
Confirm patched version is live in productionパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。
References
- patch responsibledisclosure@mattermost.com
- web nvd.nist.gov
- web github.com