vulnerability / NVI-00013165 / Revision 1
JupyterLab: Cross-site scripting (XSS) in JupyterLab via crafted language package (jupyterlab.json)
GitHub lists this reviewed advisory for jupyterlab, jupyterlab, jupyterlite-core. Published version ranges and source prerequisites are shown below; this is not an inspection of a visitor’s application.
This report has not inspected your inventory, configuration, deployed build, reachability or evidence. A catalog listing and a severity score do not establish exposure or compromise.
01 / Meaning
Why it matters
Published affected context helps an owner decide what evidence to gather. This report has not examined your application.
6.8 medium
GitHub source severity; exploitability and local consequence require separate evidence.
As of · GitHub Advisory Database
02 / Applicability
The affected context
Affected versions, configuration prerequisites and known exclusions are public. Confirm each one against the deployed service.
jupyterlab
source listed>= 4.6.0, <= 4.6.3
## Description A language pack ships a `Plural-Forms` header saying how the language counts, for example `nplurals=2; plural=(n != 1);`. JupyterLab turns that string into a function with `new Function`, so the header gets executed. The check that meant to keep it safe was a regular expression. The regex was anchored at the start but not at the end, so it accepted any string that began with a valid plural rule and ignored everything after it. A header such as the following passed the check, and the part after the plural rule ran in the JupyterLab page as soon as the first plural string was translated: ``` nplurals=2; plural=(n > 1); ``` Users are affected if all of the following are true: - they run JupyterLab 3.0.0 through 4.6.3, or an application that bundles it such as Notebook 7; - a language pack they did not write is installed in the environment; and - that language is selected, so its catalogue is loaded An installation using the default English locale loads no catalogue and is not affected. > CVE assignment pending, GitHub CNA is experiencing severe backlog ### Impact The code in the header ran in the JupyterLab page, in the same or
jupyterlab
source listed>= 3.0.0, <= 4.5.10
## Description A language pack ships a `Plural-Forms` header saying how the language counts, for example `nplurals=2; plural=(n != 1);`. JupyterLab turns that string into a function with `new Function`, so the header gets executed. The check that meant to keep it safe was a regular expression. The regex was anchored at the start but not at the end, so it accepted any string that began with a valid plural rule and ignored everything after it. A header such as the following passed the check, and the part after the plural rule ran in the JupyterLab page as soon as the first plural string was translated: ``` nplurals=2; plural=(n > 1); ``` Users are affected if all of the following are true: - they run JupyterLab 3.0.0 through 4.6.3, or an application that bundles it such as Notebook 7; - a language pack they did not write is installed in the environment; and - that language is selected, so its catalogue is loaded An installation using the default English locale loads no catalogue and is not affected. > CVE assignment pending, GitHub CNA is experiencing severe backlog ### Impact The code in the header ran in the JupyterLab page, in the same or
jupyterlite-core
source listed<= 0.8.3
## Description A language pack ships a `Plural-Forms` header saying how the language counts, for example `nplurals=2; plural=(n != 1);`. JupyterLab turns that string into a function with `new Function`, so the header gets executed. The check that meant to keep it safe was a regular expression. The regex was anchored at the start but not at the end, so it accepted any string that began with a valid plural rule and ignored everything after it. A header such as the following passed the check, and the part after the plural rule ran in the JupyterLab page as soon as the first plural string was translated: ``` nplurals=2; plural=(n > 1); ``` Users are affected if all of the following are true: - they run JupyterLab 3.0.0 through 4.6.3, or an application that bundles it such as Notebook 7; - a language pack they did not write is installed in the environment; and - that language is selected, so its catalogue is loaded An installation using the default English locale loads no catalogue and is not affected. > CVE assignment pending, GitHub CNA is experiencing severe backlog ### Impact The code in the header ran in the JupyterLab page, in the same or
03 / Response
What to do next
- investigate
Identify the exact component and deployed version, examine the linked publisher’s conditions, and retain evidence of any mitigation.
Confirm current vendor support, compatibility and deployment evidence. This report has not tested a fix in your system. GitHub Advisory Database
A fixed release is not deployment evidence.
Check current vendor support and compatibility. After making a change, verify the deployed build and relevant runtime conditions. Keep the evidence, owner and time. An updated lockfile alone does not prove what is running.
04 / Limits
What this report cannot establish
- Customer inventory, deployment, reachability and exploitation have not been inspected.
05 / Provenance
Sources you can inspect
Each assertion retains its source. Mirrored records may repeat one underlying publisher; additional links are not independent corroboration.
- GHSA-3jqq-pw4j-pqcj ↗
GitHub Advisory Database · vendor advisory
Observed . GitHub Advisory Database; CC-BY-4.0. Each advisory links its original attribution. Null normalizes fields.
Public revision history
Only published revisions appear here. Routine fetches do not create a material-change event.
- Revision 1 ·
First indexed by Null; source disclosure date is shown separately.