# CVE-2026-107778: MIT Kerberos 5 NULL pointer dereference in rd_cred

Source: https://junglewise.ai/threats/cve-2026-107778-mit-kerberos-5-krb5-through-1-22-2-contains-a-null-pointer  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-10-08. Updated: 2026-10-16  
License: CC BY 4.0 with a link back

CVE-2026-107778 · Severity: medium · CVSS 6.5 · Published 2026-10-08

MIT Kerberos 5 (krb5) is an authentication system widely used for single sign-on in corporate networks and Unix systems. A flaw in how it processes forwarded credentials allows an authenticated attacker to crash Kerberos-enabled services by sending specially crafted credential arrays, resulting in denial of service. Organizations relying on Kerberos for network authentication could experience service outages.

Technologies: [Mit Kerberos 5](https://junglewise.ai/threats/technologies/kerberos-5). Vendors: [Mit](https://junglewise.ai/threats/vendors/mit).

## Quick answers

**Is CVE-2026-107778 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-107778 being exploited in the wild.

**How severe is CVE-2026-107778?** Medium severity, with a CVSS score of 6.5, published 8 October 2026.

**Which products and versions are affected?** Mit Kerberos 5 through 1.22.2.

**Is there a fix for CVE-2026-107778?** No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

**How is CVE-2026-107778 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-107778?** Check whether you run Mit Kerberos 5 at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

A NULL pointer dereference exists in the make_cred_list() function in rd_cred.c when processing KRB-CRED messages with mismatched ticket and ticket_info array counts. An authenticated Kerberos client can trigger this crash by submitting forwarded credentials through gss_accept_sec_context() where the number of tickets exceeds the number of ticket_info entries, causing GSS-API acceptor services to crash. The vulnerability requires prior Kerberos authentication but can lead to complete denial of service for affected services.

## Affected products

- MIT Kerberos 5 through 1.22.2

## Timeline

- 2026-10-08: disclosed

## References

- [https://github.com/krb5/krb5](https://github.com/krb5/krb5)
- [https://github.com/krb5/krb5/blob/krb5-1.22.2-final/src/lib/krb5/krb/rd_cred.c](https://github.com/krb5/krb5/blob/krb5-1.22.2-final/src/lib/krb5/krb/rd_cred.c)

## Related threats

- [MIT Kerberos 5 denial of service in ASN.1 SEQUENCE OF decoding](https://junglewise.ai/threats/cve-2026-119079-decode-sequence-of-in-lib-krb5-asn-1-asn1-encode-c-in-mit)
- [MIT Kerberos 5 kadmind memory exhaustion in AUTH_GSSAPI](https://junglewise.ai/threats/cve-2026-112323-the-auth-gssapi-handler-in-lib-rpc-svc-auth-gssapi-c-in-mit)
- [MIT Kerberos 5 denial of service in kadmind AUTH_GSSAPI cleanup](https://junglewise.ai/threats/cve-2026-112322-clean-client-in-lib-rpc-svc-auth-gssapi-c-in-mit-kerberos-5-aka)
- [MIT Kerberos memory exhaustion in AUTH_GSSAPI handler](https://junglewise.ai/threats/cve-2026-112321-the-auth-gssapi-handler-in-lib-rpc-svc-auth-gssapi-c-in-mit)
- [MIT Kerberos 5 memory exhaustion via GSS-RPC authentication context leak](https://junglewise.ai/threats/cve-2026-112320-the-gss-rpc-transport-layer-in-mit-kerberos-5-aka-krb5-1-4-and)