Details of the @pixelfed security vulnerability from February 10th have now been published.
If you are still using a vulnerable version (39.5% of pixelfed instances as of today), then you should update immediately, otherwise someone may just be able to turn off federation for your instance.
https://github.com/pixelfed/pixelfed/security/advisories/GHSA-gccq-h3xj-jgvf