CVE-2026-21770

Local code execution via unsafe DLL search path

Published Jul 17, 2026 · Updated Jul 17, 2026

DLL hijacking in HCL Traveler for Microsoft Outlook before 3.0.16 allows local users to execute malicious code through unsafe library loading. HCL identifies an uncontrolled DLL search-path element but does not disclose the affected binary, DLL name, or writable directory searched. Exploitation requires high local privileges and user interaction; HCL reports that malicious content can modify or replace the application.

CVSS severity6.5
Medium
EPSS probability0.11%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

DLL hijacking in HCL Traveler for Microsoft Outlook before 3.0.16 allows local users to execute malicious code through unsafe library loading. HCL identifies an uncontrolled DLL search-path element but does not disclose the affected binary, DLL name, or writable directory searched. Exploitation requires high local privileges and user interaction; HCL reports that malicious content can modify or replace the application.

The record

CVE
CVE-2026-21770
Published
Jul 17, 2026
Updated
Jul 17, 2026
Vendor
HCLSoftware
Product
HCL Traveler for Microsoft Outlook
Classifications
CWE-427, T1574.001
Attack vector
local
Privileges
admin

Timeline

How it unfolded

  1. Jul 17, 2026CVE publishedPublication date reported by the CVE source.
  2. Jul 17, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 3.0.16

What conditions does exploitation require?

Attack vectorlocal
Required privilegesadmin

What is affected?

HCLSoftware · HCL Traveler for Microsoft Outlookversion=< 3.0.16

Published CVSS scores

6.5HCL SoftwareCVSS:3.1/AV:L/AC:L/PR:H/UI:R/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesadmin
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-427Uncontrolled Search Path Element
T1574.001DLL Search Order Hijacking

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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