CVE-2026-107778

In MIT Kerberos 5 before version 1.21.3, an attacker can modify the Extra Count field of a confidential GSS krb5 wrap token, causing the unwrapped token to appear truncated to the application.

In MIT Kerberos 5 before version 1.21.3, an attacker can cause invalid memory reads during GSS message token handling by sending message tokens with invalid length fields.

MIT krb5 through 1.22.2 contains a NULL pointer dereference vulnerability in the KDC's get_pac_princ_with_realm() that returns success while leaving the client principal NULL on malformed names. A malicious or compromised cross-realm trusted KDC can send an S4U2Proxy request with a PAC carrying a malformed client name to crash krb5kdc and deny authentication.

In MIT Kerberos 5 (krb5) before 1.22.3, an integer underflow and resultant out-of-bounds read occur if an application calls gss_accept_sec_context() on a system with a NegoEx mechanism registered in /etc/gss/mech. An unauthenticated remote attacker can trigger this, possibly causing the process to terminate in parse_message.

In MIT Kerberos 5 (krb5) before version 1.22.3, there is a NULL pointer dereference when an application calls gss_accept_sec_context() on a system with a NegoEx mechanism registered in /etc/gss/mech. An unauthenticated remote attacker can trigger this, causing the process to terminate in parse_nego_message.

A vulnerability in the MIT Kerberos implementation allows GSSAPI-protected messages using RC4-HMAC-MD5 to be spoofed due to weaknesses in the MD5 checksum design. If RC4 is preferred over stronger encryption types, an attacker could exploit MD5 collisions to forge message integrity codes.