CVE-2021-41247

LOWNVD 3.53.5—
EchelonGraph scoreMEDIUM confidence

This low-severity CVE scores 3.5 under NVD CVSS v3. EPSS exploit probability: 0.8%, top 48% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: epss, nvd
Trending — 3 sources updated this week
3.5
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS: 1%CVSS: 3.5Exploit: NoneExposed: 0

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

JupyterHub is an open source multi-user server for Jupyter notebooks. In affected versions users who have multiple JupyterLab tabs open in the same browser session, may see incomplete logout from the single-user server, as fresh credentials (for the single-user server only, not the Hub) reinstated after logout, if another active JupyterLab session is open while the logout takes place. Upgrade to JupyterHub 1.5. For distributed deployments, it is jupyterhub in the _user_ environment that needs patching. There are no patches necessary in the Hub environment. The only workaround is to make sure that only one JupyterLab tab is open when you log out.

CVSS v3
3.5
EG Score
3.5(medium)
EG Risk
21(Track)
EG Risk 21/100SSVC: 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
Severity35% × 45%
Exploitation1% × 40%
Automatability30% × 15%
Action: Routine — remediate on your standard cadence.
EPSS
52.1%
KEV
Not listed

Published

November 4, 2021

Last Modified

November 21, 2024

References (4)

Affected Packages

(1 across 1 ecosystem)
PyPI(1)
PackageVulnerable rangeFixed inDependents
jupyterhub1.0.0 ... 1.4.2 (11 versions)1.5.0—

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 13× in last 7d / 51× 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 106 total refreshes for this CVE.

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

Frequently asked(5)

What is CVE-2021-41247?
CVE-2021-41247 is a low vulnerability published on November 4, 2021. JupyterHub is an open source multi-user server for Jupyter notebooks. In affected versions users who have multiple JupyterLab tabs open in the same browser session, may see incomplete logout from the single-user server, as fresh credentials (for the single-user server only, not the Hub) reinstated…
When was CVE-2021-41247 disclosed?
CVE-2021-41247 was first published in the National Vulnerability Database on November 4, 2021, with the most recent update on November 21, 2024. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2021-41247 actively exploited?
CVE-2021-41247 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 52.1% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2021-41247?
CVE-2021-41247 has a CVSS v3 base score of 3.5 (NVD).
How do I remediate CVE-2021-41247?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2021-41247, 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

See which npm, PyPI, Go, and Maven packages are affected by CVE-2021-41247

Explore →

Is Your Infrastructure Affected by CVE-2021-41247?

EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.

Start Free Scan →Browse All CVEs