[dashmap] Unsoundness in `dashmap` references

Reference returned by some methods of Ref (and similar types) may outlive the Ref and escape the lock.
This causes undefined behavior and may result in a segfault.
More information in dashmap#167 issue.
References

https://github.com/xacrimon/dashmap/i…

[jupyter-server] Token bruteforcing

Affects: Notebook and Lab between 6.4.0?(potentially earlier) and 6.4.11 (currently latest). Jupyter Server <=1.16.0. If I am correct about the responsible code it will affect Jupyter-Server 1.17.0 and 2.0.0a0 as well.
Description: If notebook serve…

[notebook] Token bruteforcing.

Impact
What kind of vulnerability is it? Who is impacted?
Authenticated requests to the notebook server with ContentsManager.allow_hidden = False only prevented listing the contents of hidden directories, not accessing individual hidden files or files …