CVE-2026-93405

MEDIUMPre-NVD 6.16.1
EchelonGraph scoreLOW confidence

This medium-severity CVE scores 6.1 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit-prediction score not yet available (the EPSS model rescores nightly; freshly-published CVEs typically appear within 48 hours). GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: secondary
6.1EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: —CVSS: 6.1Exploit: None knownExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

Mailspring is a fast, cross-platform, open-source email client. Prior to 1.17.0, attachment quick preview converts Markdown, DOCX, and XLSX attachments with Snarkdown, Mammoth, and SheetJS and inserts the resulting HTML into the preview document through innerHTML without sanitization. A remote sender can craft a supported attachment whose converted HTML executes script when a recipient opens quick preview. The preview renderer has no direct Node or Electron access, but injected script can reach the IPC surface exposed to the quick-preview renderer. This issue alone provides script execution in the preview renderer; separate path-traversal and renderer-controlled file-write vulnerabilities are required for the documented persistent code-execution chain. This issue is fixed in version 1.17.0.

CVSS v3
6.1
EG Score
6.1(low)
EG Risk
32(Track)
EG Risk 32/100SSVC: 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 computed
Severity61% × 45%
Exploitation0% × 40%
Automatability30% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
—
EPSS %ILE
—
KEV
Not listed

Published

September 24, 2026

Last Modified

September 24, 2026

Advisory Details (4)

Auto-updated Sep 24, 2026
Patch available. Sources: github_commit, github_release, github, github_pr.
github_release Patch Available

1.17.0

Patch available: Foundry376/Mailspring 1.17.0

https://github.com/Foundry376/Mailspring/releases/tag/1.17.0
github_commit

commit 572838819966 (Foundry376/Mailspring)

Fix landed in Foundry376/Mailspring commit 572838819966 — awaiting tagged release

https://github.com/Foundry376/Mailspring/commit/5728388199666ec0a9a58f693c89c25b948a9b6c
github_pr

Add additional safeguards to attachment preview generation

Fix merged in Foundry376/Mailspring PR #2523 on 2026-01-02 — awaiting tagged release

https://github.com/Foundry376/Mailspring/pull/2523
github Patch Available

Stored XSS in Mailspring attachment quick preview (unsanitized Markdown/DOCX/XLSX conversion) · Advisory · Foundry376/Mailspring · GitHub

https://github.com/Foundry376/Mailspring/security/advisories/GHSA-px2g-jhg5-c6gh

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 3× in last 7d / 3× 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.

  1. 2026-09-24 18:35 UTCEG score recompute
  2. 2026-09-24 18:02 UTCEG score recompute
  3. 2026-09-24 18:01 UTCMITRE cvelistV5first tracked

Related CVEs(same CWE)

Frequently asked(4)

What is CVE-2026-93405?
CVE-2026-93405 is a medium vulnerability published on September 24, 2026. Mailspring is a fast, cross-platform, open-source email client. Prior to 1.17.0, attachment quick preview converts Markdown, DOCX, and XLSX attachments with Snarkdown, Mammoth, and SheetJS and inserts the resulting HTML into the preview document through innerHTML without sanitization. A remote…
When was CVE-2026-93405 disclosed?
CVE-2026-93405 was first published in the National Vulnerability Database on September 24, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
What is the CVSS score of CVE-2026-93405?
CVE-2026-93405 has a CVSS v3 base score of 6.1 (NVD). The EG score is currently aggregating — additional source signals are being incorporated as they become available..
How do I remediate CVE-2026-93405?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-93405, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

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