Plaintext password recovery via hardcoded RC4 key
Published Jun 26, 2026 · Updated Jun 26, 2026
Credential exposure in Lansweeper lsrunase 2.0 and lsencrypt 2.0 allows local users to recover plaintext passwords from encrypted values. Their password-encryption routine appends a fixed 142-byte suffix to an exposed eight-character prefix, hashes that buffer once with SHA-1, and uses the result as an RC4 key. Possession of an encrypted value and local low-privileged access are sufficient for offline recovery without brute force; integrity and availability are not directly affected.
Summary
What happened
Credential exposure in Lansweeper lsrunase 2.0 and lsencrypt 2.0 allows local users to recover plaintext passwords from encrypted values. Their password-encryption routine appends a fixed 142-byte suffix to an exposed eight-character prefix, hashes that buffer once with SHA-1, and uses the result as an RC4 key. Possession of an encrypted value and local low-privileged access are sufficient for offline recovery without brute force; integrity and availability are not directly affected.
The record
- CVE
- CVE-2026-39031
- Published
- Jun 26, 2026
- Updated
- Jun 26, 2026
- Vendor
- Unknown vendor
- Product
- Unknown product
- Classifications
- CWE-321, T1555
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Jun 26, 2026CVE publishedPublication date reported by the CVE source.
- Jun 26, 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?
What conditions does exploitation require?
What is affected?
Affected products and versions are unavailable in this record.
Published CVSS scores
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.
Weakness, pattern, technique
Public exploit references
- lsrunase2cve.py password recovery proof of conceptproof of concept · demonstrated
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Technologies
Your stack
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Your stack
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