CVE-2026-42266

HIGHPre-NVD 8.88.8—
EchelonGraph scoreMEDIUM confidence

This high-severity CVE scores 8.8 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.6%, top 56% 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, secondary
8.8EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0.9%CVSS: 8.8Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

JupyterLab is an extensible environment for interactive and reproducible computing, based on the Jupyter Notebook Architecture. From 4.0.0 to 4.5.6, the allow-list of extensions that can be installed from PyPI Extension Manager (allowed_extensions_uris) is not correctly enforced by JupyterLab. The PyPI Extension Manager was not contained to packages listed on the default PyPI index. This vulnerability is fixed in 4.5.7.

CVSS v3
8.8
EG Score
8.8HIGHmedium confidence
EG Risk
40
EG Risk 40/100

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
Severity88% × 45%
Exploitation1% × 40%
Automatability0% × 15%
EPSS PROB
0.9%
EPSS %ILE
56th
KEV
Not listed

Published

May 13, 2026

Last Modified

August 28, 2026

Advisory Details (1)

Auto-updated May 13, 2026
Patch available. Sources: github.
githubMentions a patch (unverified)

Allowlist for PyPI Extension Manager not correctly enforced, PyPI Extension Manager not limited to default PyPI index · Advisory · jupyterlab/jupyterlab · GitHub

https://github.com/jupyterlab/jupyterlab/security/advisories/GHSA-37w4-hwhx-4rc4

Vendor Advisories for CVE-2026-42266(3)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Patch Availability(2)

Vendor / EcosystemFix (by version range) / PatchReleasedSource
redhatrhoai/odh-workbench-jupyter-trustyai-cpu-py312-rhel9:17870735932026-08-27redhat
redhatmta/mta-solution-server-rhel9:17841098832026-07-21redhat

Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.

Affected Packages

(3 across 3 ecosystems)
Debian:13(1)
PackageVulnerable rangeFix by version rangeDependents
jupyterlab4.0.11+ds1+~cs11.25.27-7 ... 4.4.8+ds1+~3.1.0+~0.16.6+~cs1.4.4-1 (29 versions)
  • every version on: no fix on record
—
Debian:14(1)
PackageVulnerable rangeFix by version rangeDependents
jupyterlab4.0.11+ds1+~cs11.25.27-7 ... 4.4.8+ds1+~3.1.0+~0.16.6+~cs1.4.4-1 (25 versions)
  • every version up to 4.4.10+ds1+~3.1.0+~0.16.6+~cs1.4.4-3: fixed in 4.4.10+ds1+~3.1.0+~0.16.6+~cs1.4.4-3
—
PyPI(1)
PackageVulnerable rangeFix by version rangeDependents
jupyterlab4.0.0 ... 4.5.6 (102 versions)
  • 4.0.0 up to 4.5.7: fixed in 4.5.7
—

Weakness Classification(2)

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

Data Freshness Timeline

(refreshed 6× in last 7d / 22× 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 197 total refreshes for this CVE.

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

Related CVEs(same product + same vendor + same CWE)

Frequently asked(5)

What is CVE-2026-42266?
CVE-2026-42266 is a high vulnerability published on May 13, 2026. JupyterLab is an extensible environment for interactive and reproducible computing, based on the Jupyter Notebook Architecture. From 4.0.0 to 4.5.6, the allow-list of extensions that can be installed from PyPI Extension Manager (allowedextensionsuris) is not correctly enforced by JupyterLab. The…
When was CVE-2026-42266 disclosed?
CVE-2026-42266 was first published on May 13, 2026, with the most recent update on August 28, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-42266 actively exploited?
CVE-2026-42266 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.9% probability of exploitation in the next 30 days (56th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-42266?
CVE-2026-42266 has a CVSS base score of 8.8 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-42266?
A fix for CVE-2026-42266 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-42266 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

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