Vulnerability Instance

Possible ReDoS vulnerability in block_format in Action Mailer
There is a possible ReDoS vulnerability in the block_format helper
in Action Mailer. This vulnerability has been assigned the
CVE identifier CVE-2024-47889.

## Impact

Carefully crafted text can cause the block_format helper to take an
unexpected amount of time, possibly resulting in a DoS vulnerability.
All users running an affected release should either upgrade or apply
the relevant patch immediately.

Ruby 3.2 has mitigations for this problem, so Rails applications
using Ruby 3.2 or newer are unaffected. Rails 8.0.0.beta1 requires
Ruby 3.2 or greater so is unaffected.

## Releases

The fixed releases are available at the normal locations.

## Workarounds

Users can avoid calling the `block_format` helper or upgrade
to Ruby 3.2.

##Credits

Thanks to [ooooooo_q](https://hackerone.com/ooooooo_q) for the report!