# CVE-2026-112320: MIT Kerberos 5 memory exhaustion via GSS-RPC authentication context leak

Source: https://junglewise.ai/threats/cve-2026-112320-the-gss-rpc-transport-layer-in-mit-kerberos-5-aka-krb5-1-4-and  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-11-09. Updated: 2026-11-09  
License: CC BY 4.0 with a link back

CVE-2026-112320 · Severity: high · CVSS 7.5 · Published 2026-11-09

MIT Kerberos 5 is authentication software used by organizations to manage network access and permissions. The Kerberos administration server (kadmind) fails to clean up authentication sessions when clients switch from GSS-authenticated connections to non-GSS connections on the same network link. A remote attacker can repeatedly trigger this leak to exhaust server memory and crash the service, disrupting authentication and network access across the organization.

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

## Quick answers

**Is CVE-2026-112320 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-112320 being exploited in the wild.

**How severe is CVE-2026-112320?** High severity, with a CVSS score of 7.5, published 9 November 2026.

**Which products and versions are affected?** Mit Kerberos 5 1.4 and later.

**Is there a fix for CVE-2026-112320?** No fixed version is recorded yet. Restrict network access to kadmind to trusted hosts, or disable it in favor of kadmin.local server-side command-line tool for administration operations if possible. 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-2026-112320 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-112320?** 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.

## How to fix


Restrict network access to kadmind to trusted hosts, or disable it in favor of kadmin.local server-side command-line tool for administration operations if possible.

## Technical details

The GSS-RPC transport layer in MIT Kerberos 5 versions 1.4 and later does not properly release authentication context when a client switches from RPCSEC_GSS or AUTH_GSSAPI to a non-GSS flavor on the same TCP connection. An unauthenticated remote attacker with network access to kadmind can repeatedly establish and abandon GSS authentication contexts to trigger unbounded heap memory exhaustion, causing denial of service. No fix has been publicly released at the time of publication.

## Affected products

- MIT Kerberos 5 1.4 and later

## Timeline

- 2026-11-09: disclosed

## References

- [https://access.redhat.com/downloads/content/package-browser/](https://access.redhat.com/downloads/content/package-browser/)
- [https://access.redhat.com/security/cve/CVE-2026-112320](https://access.redhat.com/security/cve/CVE-2026-112320)

## 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 GSS-RPC unbounded memory allocation in kadmind](https://junglewise.ai/threats/cve-2026-112319-the-gss-rpc-layer-in-mit-kerberos-5-aka-krb5-does-not-enforce)