CVE-2026-39031

MEDIUMPre-NVD 5.55.5—
EchelonGraph scoreHIGH confidence

Score 5.5 from GitHub Security Advisory published 2026-06-26. CISA-ADP (Vulnrichment) CVSS v3.1 baseline 5.5; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: cisa-adp, epss, ghsa
Elevated
5.5
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS: 0%CVSS: 5.5Exploit: NoneExposed: 0

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

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.

CVSS v3
5.5
EG Score
5.5(high)
EG Risk
41(Track)
EG Risk 41/100SSVC: 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
Severity55% × 45%
Exploitation40% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS
0.6%
KEV
Not listed

Published

June 26, 2026

Last Modified

June 29, 2026

Advisory Details (1)

Auto-updated Jun 29, 2026
🔬 Proof of concept available. No patch confirmed yet.
generic🟡 PoC Available

GitHub - user6400/cve-2026-39031-lansweeper-lsrunase2-lsencrypt2: CVE-2026-39031 — offline plaintext password recovery for Lansweeper lsrunase 2.0 / lsencrypt 2.0 via a hardcoded RC4 key. PoC + technical advisory. · GitHub

https://github.com/user6400/cve-2026-39031-lansweeper-lsrunase2-lsencrypt2

Vendor Advisories for CVE-2026-39031(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 8× in last 7d / 46× 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. 2026-07-23 14:18 UTCEPSS rescore
  2. 2026-07-23 14:18 UTCEPSS rescore
  3. 2026-07-23 03:10 UTCEG score recompute
  4. 2026-07-22 14:08 UTCEPSS rescore
  5. 2026-07-21 15:24 UTCEPSS rescore
  6. 2026-07-20 17:08 UTCEPSS rescore
  7. 2026-07-18 10:04 UTCEPSS rescore
  8. 2026-07-16 17:03 UTCEPSS rescore
  9. 2026-07-16 06:49 UTCGHSA enrichment
  10. 2026-07-15 16:57 UTCEPSS rescore
  11. 2026-07-15 16:57 UTCEPSS rescore
  12. 2026-07-15 04:14 UTCGHSA enrichment
  13. 2026-07-14 02:16 UTCGHSA enrichment
  14. 2026-07-13 22:30 UTCEPSS rescore
  15. 2026-07-13 00:17 UTCGHSA enrichment
  16. 2026-07-12 05:46 UTCEPSS rescore
  17. 2026-07-11 22:19 UTCGHSA enrichment
  18. 2026-07-10 20:21 UTCGHSA enrichment
  19. 2026-07-09 19:10 UTCEPSS rescore
  20. 2026-07-09 18:23 UTCGHSA enrichment
  21. 2026-07-08 16:23 UTCGHSA enrichment
  22. 2026-07-08 15:15 UTCEPSS rescore
  23. 2026-07-07 14:25 UTCGHSA enrichment
  24. 2026-07-07 13:46 UTCEPSS rescore
  25. 2026-07-06 16:27 UTCEPSS rescore
Show 21 more
  1. 2026-07-06 16:27 UTCEPSS rescore
  2. 2026-07-06 12:23 UTCGHSA enrichment
  3. 2026-07-06 02:23 UTCEPSS rescore
  4. 2026-07-06 02:23 UTCEPSS rescore
  5. 2026-07-05 10:24 UTCGHSA enrichment
  6. 2026-07-04 08:26 UTCGHSA enrichment
  7. 2026-07-04 06:31 UTCEPSS rescore
  8. 2026-07-03 06:28 UTCGHSA enrichment
  9. 2026-07-03 06:26 UTCGHSA enrichment
  10. 2026-07-02 04:26 UTCGHSA enrichment
  11. 2026-07-01 15:06 UTCEPSS rescore
  12. 2026-07-01 02:29 UTCGHSA enrichment
  13. 2026-06-30 23:22 UTCEPSS rescore
  14. 2026-06-30 00:31 UTCEG score recompute▲ 5.50
  15. 2026-06-30 00:31 UTCGHSA enrichment
  16. 2026-06-29 14:52 UTCMITRE cvelistV5CVSS v3 → 5.5 · severity → MEDIUM
  17. 2026-06-29 14:06 UTCEPSS rescore
  18. 2026-06-28 14:07 UTCEPSS rescore
  19. 2026-06-28 04:56 UTCEPSS rescore
  20. 2026-06-26 21:37 UTCEG score recompute
  21. 2026-06-26 21:37 UTCGHSA enrichment

Frequently asked(5)

What is CVE-2026-39031?
CVE-2026-39031 is a medium vulnerability published on June 26, 2026. 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…
When was CVE-2026-39031 disclosed?
CVE-2026-39031 was first published in the National Vulnerability Database on June 26, 2026, with the most recent update on June 29, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-39031 actively exploited?
CVE-2026-39031 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.6% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-39031?
CVE-2026-39031 has a CVSS v3.1 base score of 5.5 (CISA-ADP / Vulnrichment enrichment; NVD's own analysis pending).
How do I remediate CVE-2026-39031?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-39031, 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-2026-39031

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