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
CVE-2026-75588
Score 2.6 from GitHub Security Advisory (severity: LOW) published 2026-09-17. a secondary CVSS source baseline 2.6; sources differ by 0.0.
- Lower severity and no public exploit yet
No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.
- CVSS v3
- 2.6
- EG Score
- 2.6(high)
- EG Risk
- 12(Track)EG Risk 12/100SSVC: Track
EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).
How it’s computedSeverity26% × 45%Exploitation0% × 40%Automatability0% × 15%Action: Routine — remediate on your standard cadence. - EPSS PROB
- 0%
- EPSS %ILE
- 6%
- KEV
- Not listed
Published
September 17, 2026
Last Modified
September 18, 2026
References (1)
- responsibledisclosure@mattermosthttps://mattermost.com/security-updates
Vendor Advisories for CVE-2026-75588(1)
These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.
Weakness Classification(1)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Data Freshness Timeline
(refreshed 9× in last 7d / 9× in last 30d)
Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.
- 2026-09-18 19:28 UTCEPSS rescore
- 2026-09-18 14:00 UTCGHSA enrichment
- 2026-09-17 20:27 UTCEG score recompute
- 2026-09-17 20:27 UTCGHSA enrichment
- 2026-09-17 19:30 UTCEG score recompute
- 2026-09-17 19:30 UTCGHSA enrichment
- 2026-09-17 17:57 UTCEG score recompute
- 2026-09-17 15:25 UTCEG score recompute
- 2026-09-17 15:24 UTCMITRE cvelistV5first tracked
Frequently asked(5)
What is CVE-2026-75588?
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Dependency Blast Radius
Explore the affected products and dependency analysis for CVE-2026-75588
Is Your Infrastructure Affected by CVE-2026-75588?
EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.