CVE-2026-66749

MEDIUMPre-NVD 6.56.5—
EchelonGraph scoreMEDIUM confidence

Score 6.5 from GitHub Security Advisory (severity: HIGH) published 2026-07-28. a secondary CVSS source baseline 6.5; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
Trending — 3 sources updated this week
6.5EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 6.5Exploit: None knownExposed: 0

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

Let's Chat 0.4.0 through 0.4.8 contains a null dereference vulnerability that allows authenticated attackers to crash the server by supplying a valid 24-character hex string room parameter that matches no document in the database. Attackers can send a crafted GET /messages request causing an uncaught TypeError in an asynchronous Mongoose callback that terminates the Node.js server process, with the same defect reachable through multiple code paths including the socket.io interface.

CVSS v3
6.5
EG Score
6.5(medium)
EG Risk
29(Track)
EG Risk 29/100SSVC: 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
Severity65% × 45%
Exploitation0% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
23%
KEV
Not listed

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 0.4.0 - 0.4.8 Denial of Service via Null Dereference in Room Lookup | Advisories | VulnCheck

https://www.vulncheck.com/advisories/let-s-chat-denial-of-service-via-null-dereference-in-room-lookup
generic

GitHub - theopaid/Unchecked-Room-Lookup-Leads-to-Server-Crash-Let-s-Chat-: Security Advisory: Unchecked Room Lookup Leads to Server Crash (Let's Chat) · GitHub

https://github.com/theopaid/Unchecked-Room-Lookup-Leads-to-Server-Crash-Let-s-Chat-

Vendor Advisories for CVE-2026-66749(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 16× in last 7d / 76× 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. 2026-08-30 01:22 UTCEPSS rescore
  2. 2026-08-29 23:32 UTCEG score recompute
  3. 2026-08-29 23:32 UTCGHSA enrichment
  4. 2026-08-28 21:42 UTCEPSS rescore
  5. 2026-08-27 20:57 UTCEG score recompute
  6. 2026-08-27 20:57 UTCGHSA enrichment
  7. 2026-08-26 19:52 UTCEG score recompute
  8. 2026-08-26 19:52 UTCGHSA enrichment
  9. 2026-08-26 14:47 UTCEPSS rescore
  10. 2026-08-25 19:52 UTCEG score recompute
  11. 2026-08-25 19:52 UTCGHSA enrichment
  12. 2026-08-25 13:49 UTCEPSS rescore
  13. 2026-08-24 19:49 UTCEG score recompute
  14. 2026-08-24 19:49 UTCGHSA enrichment
  15. 2026-08-23 19:49 UTCEG score recompute
  16. 2026-08-23 19:49 UTCGHSA enrichment
  17. 2026-08-23 00:19 UTCEPSS rescore
  18. 2026-08-22 19:49 UTCEG score recompute
  19. 2026-08-22 19:49 UTCGHSA enrichment
  20. 2026-08-21 23:49 UTCEPSS rescore
  21. 2026-08-21 19:48 UTCEG score recompute
  22. 2026-08-21 19:48 UTCGHSA enrichment
  23. 2026-08-20 22:56 UTCEPSS rescore
  24. 2026-08-20 19:47 UTCGHSA enrichment
  25. 2026-08-19 19:47 UTCEG score recompute
Show 62 more
  1. 2026-08-19 19:47 UTCGHSA enrichment
  2. 2026-08-19 17:04 UTCEPSS rescore
  3. 2026-08-18 18:39 UTCEG score recompute
  4. 2026-08-18 18:39 UTCGHSA enrichment
  5. 2026-08-18 13:48 UTCEPSS rescore
  6. 2026-08-17 16:55 UTCEG score recompute
  7. 2026-08-17 16:55 UTCGHSA enrichment
  8. 2026-08-17 13:47 UTCEPSS rescore
  9. 2026-08-16 16:55 UTCEG score recompute
  10. 2026-08-16 16:55 UTCGHSA enrichment
  11. 2026-08-16 14:56 UTCEPSS rescore
  12. 2026-08-15 16:55 UTCEG score recompute
  13. 2026-08-15 16:55 UTCGHSA enrichment
  14. 2026-08-15 01:30 UTCEPSS rescore
  15. 2026-08-14 16:54 UTCEG score recompute
  16. 2026-08-14 16:54 UTCGHSA enrichment
  17. 2026-08-13 22:00 UTCEPSS rescore
  18. 2026-08-13 16:53 UTCGHSA enrichment
  19. 2026-08-12 16:53 UTCEG score recompute
  20. 2026-08-12 16:53 UTCGHSA enrichment
  21. 2026-08-12 13:51 UTCEPSS rescore
  22. 2026-08-11 16:52 UTCEG score recompute
  23. 2026-08-11 16:52 UTCGHSA enrichment
  24. 2026-08-11 00:00 UTCEPSS rescore
  25. 2026-08-10 16:52 UTCGHSA enrichment
  26. 2026-08-09 16:51 UTCEG score recompute
  27. 2026-08-09 16:51 UTCGHSA enrichment
  28. 2026-08-09 13:47 UTCEPSS rescore
  29. 2026-08-08 16:51 UTCGHSA enrichment
  30. 2026-08-07 16:50 UTCEG score recompute
  31. 2026-08-07 16:50 UTCGHSA enrichment
  32. 2026-08-06 16:50 UTCEG score recompute
  33. 2026-08-06 16:50 UTCGHSA enrichment
  34. 2026-08-06 13:47 UTCEPSS rescore
  35. 2026-08-05 19:17 UTCEPSS rescore
  36. 2026-08-05 19:17 UTCEPSS rescore
  37. 2026-08-05 16:50 UTCGHSA enrichment
  38. 2026-08-04 16:49 UTCEG score recompute
  39. 2026-08-04 16:49 UTCGHSA enrichment
  40. 2026-08-04 15:10 UTCEPSS rescore
  41. 2026-08-04 10:39 UTCEPSS rescore
  42. 2026-08-03 16:48 UTCEG score recompute
  43. 2026-08-03 16:48 UTCGHSA enrichment
  44. 2026-08-03 10:36 UTCEPSS rescore
  45. 2026-08-02 16:48 UTCEG score recompute
  46. 2026-08-02 16:48 UTCGHSA enrichment
  47. 2026-08-02 02:27 UTCEPSS rescore
  48. 2026-08-01 16:47 UTCEG score recompute
  49. 2026-08-01 16:47 UTCGHSA enrichment
  50. 2026-08-01 04:16 UTCEPSS rescore
  51. 2026-07-31 16:46 UTCGHSA enrichment
  52. 2026-07-30 16:45 UTCEG score recompute
  53. 2026-07-30 16:45 UTCGHSA enrichment
  54. 2026-07-30 16:28 UTCEPSS rescore
  55. 2026-07-30 01:30 UTCEPSS rescore
  56. 2026-07-29 17:24 UTCEG score recompute
  57. 2026-07-29 17:24 UTCGHSA enrichment
  58. 2026-07-28 17:24 UTCEG score recompute
  59. 2026-07-28 16:56 UTCEG score recompute
  60. 2026-07-28 16:40 UTCEG score recompute
  61. 2026-07-28 16:14 UTCEG score recompute
  62. 2026-07-28 16:13 UTCMITRE cvelistV5first tracked

Frequently asked(5)

What is CVE-2026-66749?
CVE-2026-66749 is a medium vulnerability published on July 28, 2026. Let's Chat 0.4.0 through 0.4.8 contains a null dereference vulnerability that allows authenticated attackers to crash the server by supplying a valid 24-character hex string room parameter that matches no document in the database. Attackers can send a crafted GET /messages request causing an…
When was CVE-2026-66749 disclosed?
CVE-2026-66749 was first published in the National Vulnerability Database 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-2026-66749 actively exploited?
CVE-2026-66749 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 76.6% of all scored CVEs.
What is the CVSS score of CVE-2026-66749?
CVE-2026-66749 has a CVSS v3 base score of 6.5 (NVD).
How do I remediate CVE-2026-66749?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-66749, 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

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