CVE-2026-21770

MEDIUMPre-NVD 6.56.5—
EchelonGraph scoreHIGH confidence

Score 6.5 from GitHub Security Advisory published 2026-07-17. a secondary CVSS source baseline 6.5; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
6.5
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS: 0%CVSS: 6.5Exploit: NoneExposed: 0

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

HCL Traveler for Microsoft Outlook (HTMO) is susceptible to a DLL hijacking vulnerability which could allow an attacker to modify or replace the application with malicious content.

CVSS v3
6.5
EG Score
6.5(high)
EG Risk
29(Track)
EG Risk 29/100SSVC: 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
Severity65% × 45%
Exploitation0% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS
1.5%
KEV
Not listed

Published

July 17, 2026

Last Modified

July 17, 2026

Advisory Details (1)

Auto-updated Jul 17, 2026
No patch confirmed yet.
generic

Security Bulletin: HCL Traveler for Microsoft Outlook (HTMO) is susceptible to DLL hijacking (CVE-2026-21770) - Customer Support

https://support.hcl-software.com/csm?id=kb_article&sysparm_article=KB0130919

Vendor Advisories for CVE-2026-21770(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 12× in last 7d / 23× 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. 2026-07-25 14:17 UTCEPSS rescore
  2. 2026-07-25 14:17 UTCEPSS rescore
  3. 2026-07-24 14:17 UTCEPSS rescore
  4. 2026-07-23 14:18 UTCEPSS rescore
  5. 2026-07-23 14:18 UTCEPSS rescore
  6. 2026-07-23 03:06 UTCEG score recompute
  7. 2026-07-22 14:08 UTCEPSS rescore
  8. 2026-07-21 15:24 UTCEPSS rescore
  9. 2026-07-21 15:24 UTCEPSS rescore
  10. 2026-07-20 17:08 UTCEPSS rescore
  11. 2026-07-19 14:31 UTCEPSS rescore
  12. 2026-07-19 14:31 UTCEPSS rescore
  13. 2026-07-18 11:54 UTCEG score recompute
  14. 2026-07-18 11:54 UTCGHSA enrichment
  15. 2026-07-18 10:04 UTCEPSS rescore
  16. 2026-07-18 10:04 UTCEPSS rescore
  17. 2026-07-17 16:00 UTCEG score recompute
  18. 2026-07-17 16:00 UTCGHSA enrichment
  19. 2026-07-17 13:35 UTCEG score recompute
  20. 2026-07-17 13:35 UTCGHSA enrichment
  21. 2026-07-17 06:53 UTCGHSA enrichment
  22. 2026-07-17 04:50 UTCEG score recompute
  23. 2026-07-17 04:49 UTCMITRE cvelistV5first tracked

Frequently asked(5)

What is CVE-2026-21770?
CVE-2026-21770 is a medium vulnerability published on July 17, 2026. HCL Traveler for Microsoft Outlook (HTMO) is susceptible to a DLL hijacking vulnerability which could allow an attacker to modify or replace the application with malicious content.
When was CVE-2026-21770 disclosed?
CVE-2026-21770 was first published in the National Vulnerability Database on July 17, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-21770 actively exploited?
CVE-2026-21770 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 1.5% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-21770?
CVE-2026-21770 has a CVSS v3 base score of 6.5 (NVD).
How do I remediate CVE-2026-21770?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-21770, 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

Explore the affected products and dependency analysis for CVE-2026-21770

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