CVE-2026-102830

MEDIUMPre-NVD 6.86.8—
EchelonGraph scoreMEDIUM confidence

This medium-severity CVE scores 6.8 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.3% (16th percentile of EPSS-scored CVEs). 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
Trending — 3 sources updated this week
6.8EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0.3%CVSS: 6.8Exploit: 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 JupyterLab 3.0.0 until 4.5.11 and 4.6.4, and in JupyterLite Core 0.8.3 and earlier, the Plural-Forms header in a selected third-party language pack can append JavaScript after a valid plural rule because prefix-only regular-expression validation accepts a matching prefix without requiring the entire header to match. JupyterLab passes the accepted expression to new Function, so loading the catalogue and translating a plural string executes the appended code in the authenticated JupyterLab origin. Where Jupyter Server kernels, terminals, and APIs are exposed, the code can use authenticated server APIs to read or modify files and run code. Impact is much more limited in JupyterLite because it typically lacks most exposed Jupyter Server surfaces. The default English locale is unaffected because it does not load a translation catalogue. This issue is fixed in JupyterLab 4.5.11 and 4.6.4 and JupyterLite Core 0.8.4.

CVSS v3
6.8
EG Score
6.8MEDIUMmedium 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
Severity68% × 45%
Exploitation0% × 40%
Automatability30% × 15%
CISA SSVC: Track at low or medium mission impact; Track or Attend at high (mission-essential systems).
Action: A fix is available. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high.
EPSS PROB
0.3%
EPSS %ILE
16th
KEV
Not listed

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

A fix is available. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high.

Exploitation none (no KEV listing, exploit record or EPSS ≥ 50%) · Automatable unknown (not published for this CVE) · Technical impact partial (CVSS below 9.0). 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

September 29, 2026

Last Modified

September 29, 2026

Advisory Details (6)

Auto-updated Sep 29, 2026
Patch available. Sources: github, github_commit, github_release.
github_release Patch Available

v4.6.4

Patch available: jupyterlab/jupyterlab v4.6.4

https://github.com/jupyterlab/jupyterlab/releases/tag/v4.6.4
github_release Patch Available

v4.5.11

Patch available: jupyterlab/jupyterlab v4.5.11

https://github.com/jupyterlab/jupyterlab/releases/tag/v4.5.11
github_commit

commit f9de43dc565a (jupyterlab/jupyterlab)

Fix landed in jupyterlab/jupyterlab commit f9de43dc565a — awaiting tagged release

https://github.com/jupyterlab/jupyterlab/commit/f9de43dc565a1118120d466117f877a189a4ce90
github_commit

commit de324ae91346 (jupyterlab/jupyterlab)

Fix landed in jupyterlab/jupyterlab commit de324ae91346 — awaiting tagged release

https://github.com/jupyterlab/jupyterlab/commit/de324ae91346c713c4f5e5485f97b6e914e0f774
github_commit

commit 985a3223cd77 (jupyterlab/jupyterlab)

Fix landed in jupyterlab/jupyterlab commit 985a3223cd77 — awaiting tagged release

https://github.com/jupyterlab/jupyterlab/commit/985a3223cd77fd4f991cd90066342a90711d70f6
github Patch Available

Code injection in JupyterLab via a language pack's plural forms header · Advisory · jupyterlab/jupyterlab · GitHub

https://github.com/jupyterlab/jupyterlab/security/advisories/GHSA-3jqq-pw4j-pqcj

Vendor Advisories for CVE-2026-102830(1)

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

Affected Packages

(2 across 1 ecosystem)
PyPI(2)
PackageVulnerable rangeFixed inDependents
jupyterlab4.6.0, 4.6.1, 4.6.2, 4.6.34.6.4—
jupyterlite-core0.0.0a0 ... 0.8.3 (100 versions)0.8.4—

Weakness Classification(2)

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

Data Freshness Timeline

(refreshed 10× in last 7d / 10× 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. 2026-10-04 01:50 UTCEG score recompute
  2. 2026-10-03 14:25 UTCEPSS rescore
  3. 2026-10-03 00:56 UTCEG score recompute
  4. 2026-10-02 00:01 UTCEG score recompute
  5. 2026-10-01 19:49 UTCEPSS rescore
  6. 2026-09-30 22:46 UTCEG score recompute
  7. 2026-09-30 15:02 UTCEPSS rescore
  8. 2026-09-29 19:20 UTCEG score recompute
  9. 2026-09-29 19:00 UTCEG score recompute
  10. 2026-09-29 18:58 UTCMITRE cvelistV5first tracked

Related CVEs(same product + same CWE)

Frequently asked(5)

What is CVE-2026-102830?
CVE-2026-102830 is a medium vulnerability published on September 29, 2026. JupyterLab is an extensible environment for interactive and reproducible computing, based on the Jupyter Notebook Architecture. From JupyterLab 3.0.0 until 4.5.11 and 4.6.4, and in JupyterLite Core 0.8.3 and earlier, the Plural-Forms header in a selected third-party language pack can append…
When was CVE-2026-102830 disclosed?
CVE-2026-102830 was first published on September 29, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-102830 actively exploited?
CVE-2026-102830 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.3% probability of exploitation in the next 30 days (16th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-102830?
CVE-2026-102830 has a CVSS base score of 6.8 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-102830?
A fix for CVE-2026-102830 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-102830 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

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