CVE-2026-39031

Lansweeper Credential Storage RC4 Key Exposure

Published Jun 26, 2026 CVSS 3.1 · 5.5 Medium EPSS < 1% KEV · Not listed
Description
Lansweeper lsrunase 2.0 and lsencrypt 2.0 use RC4 encryption with a hardcoded 142-byte static key array to encrypt credentials. An 8-character prefix is stored in cleartext alongside the ciphertext. This allows an attacker with local access to recover any encrypted password to plaintext using a single SHA-1 hash and RC4 decryption operation, with no brute force required.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
First Time appeared Lansweeper
Lansweeper lsencrypt
Lansweeper lsrunase
Vendors & Products Lansweeper
Lansweeper lsencrypt
Lansweeper lsrunase
Type Values Removed Values Added
Title Lansweeper Credential Storage RC4 Key Exposure
Type Values Removed Values Added
Title Local Credential Disclosure via Hardcoded RC4 Key in Lansweeper lsrunase 2.0 and lsencrypt 2.0
Weaknesses CWE-327
CWE-330
Type Values Removed Values Added
Weaknesses CWE-321
Metrics cvssV3_1

{'score': 5.5, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N'}

ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'poc', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
Title Local Credential Disclosure via Hardcoded RC4 Key in Lansweeper lsrunase 2.0 and lsencrypt 2.0
Weaknesses CWE-327
CWE-330
Type Values Removed Values Added
Description Lansweeper lsrunase 2.0 and lsencrypt 2.0 use RC4 encryption with a hardcoded 142-byte static key array to encrypt credentials. An 8-character prefix is stored in cleartext alongside the ciphertext. This allows an attacker with local access to recover any encrypted password to plaintext using a single SHA-1 hash and RC4 decryption operation, with no brute force required.
References
Weaknesses

Sources

Status
PUBLISHED
Assigner
mitre
Published
Updated
Jun 29, 2026, 1:37 PM
Reserved
Apr 6, 2026, 12:00 AM
Status
Deferred
Published
Jun 26, 2026, 9:16 PM
Modified
Jun 29, 2026, 7:27 PM