In MIT Kerberos 5 (aka krb5) before 1.21.3, an attacker can modify the plaintext Extra Count field of a confidential GSS krb5 wrap token, causing the unwrapped token to appear truncated to the application.
https://web.mit.edu/kerberos/www/advisories/
https://github.com/krb5/krb5/commit/55fbf435edbe2e92dd8101669b1ce7144bc96fef