Several components in Spring Security compare security-sensitive values using standard string equality (String.equals()) rather than a constant-time comparison. Because String.equals() returns as soon as it finds a differing character, the time taken to reject an incorrect value is proportional to the number of leading characters that match the expected value.
Spring Security 7.1.0
Spring Security 7.0.0 - 7.0.6
Spring Security 6.5.0 - 6.5.11
Spring Security 6.4.0 - 6.4.18
Spring Security 5.8.0 - 5.8.27
Spring Security 5.7.0 - 5.7.25