Drupal Core has a rarely used feature, provided by an underlying library, which allows certain attributes of incoming HTTP requests to be overridden.
This functionality can be abused in a way that may cause Drupal to cache response data that it should not. This can lead to legitimate requests receiving inappropriate cached responses (cache poisoning).
This could be exploited in various ways:
Changes are being made in the underlying library which will mitigate this problem, but in the meantime Drupal core has been hardened to protect against this vulnerability.
{
"constraint": ">= 8.0.0 < 10.4.9"
}{
"constraint": ">= 10.5.0 < 10.5.6"
}