This is the description I posted in the changelog:
TROVE-2020-002 is a vulnerability affecting all released Tor instances since 0.2.1.5-alpha. Using this vulnerability, an attacker could cause Tor instances to consume a huge amount of CPU, disrupting their operations for several seconds or minutes. This attack could be launched by anybody against a relay, or by a directory cache against any client that had connected to it. The attacker could launch this attack as much as they wanted, thereby disrupting service or creating patterns that could aid in traffic analysis. This issue was found by OSS-Fuzz, and is also tracked as CVE-2020-10592.
I will post a more detailed analysis in a week or so.
This issue is fixed in today's Tor releases: 0.3.5.10, 0.4.1.9, 0.4.2.7, and 0.4.3.3-alpha.