CVE-2026-66750

MEDIUMPre-NVD 4.34.3—
EchelonGraph scoreMEDIUM confidence

Score 4.3 from GitHub Security Advisory published 2026-07-28. A secondary CVSS source baseline 4.3; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
Trending — 3 sources updated this weekElevated
4.3EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0.3%CVSS: 4.3Exploit: Elevated riskExposed services: Not assessed

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

Let's Chat 0.3.0 through 0.4.8 contains a broken access control vulnerability that allows authenticated attackers to download file attachments from private and password-protected rooms they are not a member of by exploiting missing room membership checks in the file retrieval route. Attackers can enumerate adjacent MongoDB ObjectIds derived from a known file ID to recover files uploaded by other users, as the GET /files/:id/:name route in app/controllers/files.js only enforces login authentication without consulting room membership or the Room.canJoin check.

CVSS v3
4.3
EG Score
4.3MEDIUMmedium confidence
EG Risk
35
EG Risk 35/100CISA SSVC

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
Severity43% × 45%
Exploitation40% × 40%
Automatability0% × 15%
CISA SSVC: Track at low or medium mission impact; Track* at high (mission-essential systems).
Action: No fix is confirmed yet. Restrict network exposure of the affected system or apply the vendor's mitigation within your standard update timelines, and watch the vendor's advisory for the fix.
EPSS PROB
0.3%
EPSS %ILE
25th
KEV
Not listed

CISA SSVCTrack at low or medium mission impact; Track* at high (mission-essential systems).

No fix is confirmed yet. Restrict network exposure of the affected system or apply the vendor's mitigation within your standard update timelines, and watch the vendor's advisory for the fix.

Exploitation public PoC (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). Mission impact is CISA's Mission & Well-being decision point, and only you can judge it: high means the affected system is essential to your organisation's mission, or its compromise could cause irreversible harm to people. CISA's decision table

Published

July 28, 2026

Last Modified

July 30, 2026

Advisory Details (2)

Auto-updated Jul 28, 2026
No patch confirmed yet.
generic

Let's Chat 0.3.0 - 0.4.8 Broken Access Control File Disclosure via GET /files route | Advisories | VulnCheck

https://www.vulncheck.com/advisories/let-s-chat-broken-access-control-file-disclosure-via-get-files-route
generic

GitHub - theopaid/Insufficient-Access-Controls-Allow-for-Unauthorized-File-Downloads-Let-s-Chat-: Security Advisory: Insufficient Access Controls Allow for Unauthorized File Downloads (Let's Chat) · GitHub

https://github.com/theopaid/Insufficient-Access-Controls-Allow-for-Unauthorized-File-Downloads-Let-s-Chat-

Vendor Advisories for CVE-2026-66750(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 14× in last 7d / 61× 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.

Showing the most recent 100 of 150 total refreshes for this CVE.

  1. 2026-09-29 07:46 UTCEG score recompute
  2. 2026-09-29 07:46 UTCGHSA enrichment
  3. 2026-09-28 13:52 UTCEPSS rescore
  4. 2026-09-28 03:23 UTCEG score recompute
  5. 2026-09-28 03:23 UTCGHSA enrichment
  6. 2026-09-27 13:48 UTCEPSS rescore
  7. 2026-09-26 15:59 UTCEPSS rescore
  8. 2026-09-25 06:14 UTCEG score recompute
  9. 2026-09-25 06:14 UTCGHSA enrichment
  10. 2026-09-23 21:55 UTCEG score recompute
  11. 2026-09-23 21:55 UTCGHSA enrichment
  12. 2026-09-23 17:54 UTCEPSS rescore
  13. 2026-09-22 21:41 UTCEG score recompute
  14. 2026-09-22 21:41 UTCGHSA enrichment
  15. 2026-09-20 20:16 UTCEPSS rescore
  16. 2026-09-20 05:39 UTCEG score recompute
  17. 2026-09-20 05:39 UTCGHSA enrichment
  18. 2026-09-19 05:16 UTCEG score recompute
  19. 2026-09-19 05:16 UTCGHSA enrichment
  20. 2026-09-18 19:28 UTCEPSS rescore
  21. 2026-09-18 02:06 UTCEG score recompute
  22. 2026-09-18 02:06 UTCGHSA enrichment
  23. 2026-09-16 14:08 UTCEPSS rescore
  24. 2026-09-16 11:50 UTCEG score recompute
  25. 2026-09-16 11:50 UTCGHSA enrichment
Show 75 more
  1. 2026-09-16 05:15 UTCEPSS rescore
  2. 2026-09-15 08:39 UTCEG score recompute
  3. 2026-09-15 08:39 UTCGHSA enrichment
  4. 2026-09-14 08:28 UTCEG score recompute
  5. 2026-09-14 08:28 UTCGHSA enrichment
  6. 2026-09-13 08:33 UTCEG score recompute
  7. 2026-09-13 08:33 UTCGHSA enrichment
  8. 2026-09-12 08:38 UTCEG score recompute
  9. 2026-09-12 08:38 UTCGHSA enrichment
  10. 2026-09-11 14:53 UTCEPSS rescore
  11. 2026-09-11 08:02 UTCEG score recompute
  12. 2026-09-11 08:01 UTCGHSA enrichment
  13. 2026-09-10 07:58 UTCGHSA enrichment
  14. 2026-09-09 08:02 UTCEG score recompute
  15. 2026-09-09 08:02 UTCGHSA enrichment
  16. 2026-09-08 22:01 UTCEPSS rescore
  17. 2026-09-07 20:55 UTCEG score recompute
  18. 2026-09-07 20:55 UTCGHSA enrichment
  19. 2026-09-07 16:01 UTCEPSS rescore
  20. 2026-09-06 19:12 UTCEG score recompute
  21. 2026-09-06 19:12 UTCGHSA enrichment
  22. 2026-09-06 13:47 UTCEPSS rescore
  23. 2026-09-05 19:10 UTCEG score recompute
  24. 2026-09-05 19:10 UTCGHSA enrichment
  25. 2026-09-05 15:31 UTCEPSS rescore
  26. 2026-09-04 12:01 UTCEG score recompute
  27. 2026-09-04 12:01 UTCGHSA enrichment
  28. 2026-09-04 05:07 UTCEPSS rescore
  29. 2026-09-02 14:12 UTCEPSS rescore
  30. 2026-09-02 00:51 UTCEG score recompute
  31. 2026-09-02 00:51 UTCGHSA enrichment
  32. 2026-09-01 13:54 UTCEPSS rescore
  33. 2026-09-01 04:40 UTCEPSS rescore
  34. 2026-09-01 00:46 UTCGHSA enrichment
  35. 2026-08-30 23:27 UTCEG score recompute
  36. 2026-08-30 23:27 UTCGHSA enrichment
  37. 2026-08-30 19:17 UTCEPSS rescore
  38. 2026-08-30 01:22 UTCEPSS rescore
  39. 2026-08-29 23:32 UTCEG score recompute
  40. 2026-08-29 23:32 UTCGHSA enrichment
  41. 2026-08-28 21:42 UTCEPSS rescore
  42. 2026-08-27 20:57 UTCEG score recompute
  43. 2026-08-27 20:57 UTCGHSA enrichment
  44. 2026-08-26 19:41 UTCEG score recompute
  45. 2026-08-26 19:41 UTCGHSA enrichment
  46. 2026-08-26 14:47 UTCEPSS rescore
  47. 2026-08-25 19:17 UTCEG score recompute
  48. 2026-08-25 19:17 UTCGHSA enrichment
  49. 2026-08-25 13:49 UTCEPSS rescore
  50. 2026-08-24 19:23 UTCEG score recompute
  51. 2026-08-24 19:23 UTCGHSA enrichment
  52. 2026-08-23 19:27 UTCEG score recompute
  53. 2026-08-23 19:27 UTCGHSA enrichment
  54. 2026-08-23 00:19 UTCEPSS rescore
  55. 2026-08-22 19:32 UTCEG score recompute
  56. 2026-08-22 19:32 UTCGHSA enrichment
  57. 2026-08-21 23:49 UTCEPSS rescore
  58. 2026-08-21 19:37 UTCEG score recompute
  59. 2026-08-21 19:37 UTCGHSA enrichment
  60. 2026-08-20 22:56 UTCEPSS rescore
  61. 2026-08-20 19:42 UTCGHSA enrichment
  62. 2026-08-19 19:47 UTCEG score recompute
  63. 2026-08-19 19:47 UTCGHSA enrichment
  64. 2026-08-19 17:04 UTCEPSS rescore
  65. 2026-08-18 18:39 UTCEG score recompute
  66. 2026-08-18 18:39 UTCGHSA enrichment
  67. 2026-08-18 13:48 UTCEPSS rescore
  68. 2026-08-17 15:23 UTCEG score recompute
  69. 2026-08-17 15:23 UTCGHSA enrichment
  70. 2026-08-17 13:47 UTCEPSS rescore
  71. 2026-08-16 15:28 UTCEG score recompute
  72. 2026-08-16 15:28 UTCGHSA enrichment
  73. 2026-08-16 14:56 UTCEPSS rescore
  74. 2026-08-15 15:33 UTCEG score recompute
  75. 2026-08-15 15:33 UTCGHSA enrichment

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Frequently asked(5)

What is CVE-2026-66750?
CVE-2026-66750 is a medium vulnerability published on July 28, 2026. Let's Chat 0.3.0 through 0.4.8 contains a broken access control vulnerability that allows authenticated attackers to download file attachments from private and password-protected rooms they are not a member of by exploiting missing room membership checks in the file retrieval route. Attackers can…
When was CVE-2026-66750 disclosed?
CVE-2026-66750 was first published on July 28, 2026, with the most recent update on July 30, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-66750 actively exploited?
CVE-2026-66750 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.3% probability of exploitation in the next 30 days (25th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-66750?
CVE-2026-66750 has a CVSS base score of 4.3 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-66750?
No fix for CVE-2026-66750 is confirmed yet. Until one is published, restrict network exposure of the affected system or apply the vendor's mitigation — for example, keep it off the internet or limit it to trusted networks — and watch the vendor's advisory for the fix. The vendor advisories EchelonGraph has for CVE-2026-66750 are linked in the Vendor Advisories panel on this page.

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