CVE-2026-112319
Description
The GSS-RPC layer in MIT Kerberos 5 (aka krb5) does not enforce size limits on XDR-decoded data, which allows remote authenticated users to cause a denial of service (memory exhaustion or excessive CPU consumption in kadmind) via crafted RPC requests that trigger unbounded memory allocations during XDR decoding.
Statement
This vulnerability is rated as having an Important severity because an authenticated remote client can trigger repeated unbounded memory allocations and memory leaks in services relying on Kerberos RPC, causing denial of service. While exploitation requires establishing a valid Kerberos security context, the flaw can be leveraged against network-facing services such as the Kerberos administration daemon (kadmind). Because the issue only affects process availability and does not permit unauthorized data disclosure, data alteration, or code execution, it does not meet the threshold for Critical.
Mitigation
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.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
The following CVSS metrics and score provided are preliminary and subject to review.
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 6.5 | N/A | 6.5 |
| Attack Vector | Network | N/A | Network |
| Attack Complexity | Low | N/A | Low |
| Privileges Required | Low | N/A | Low |
| User Interaction | None | N/A | None |
| Scope | Unchanged | N/A | Unchanged |
| Confidentiality | None | N/A | None |
| Integrity Impact | None | N/A | None |
| Availability Impact | High | N/A | High |
Vector
Red Hat: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
cve.org: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Understanding the Weakness (CWE)
Availability
Technical Impact: DoS: Resource Consumption (CPU); DoS: Resource Consumption (Memory); DoS: Resource Consumption (Other)
When allocating resources without limits, an attacker could prevent other systems, applications, or processes from accessing the same type of resource. It can be easy for an attacker to consume many resources by rapidly making many requests or causing larger resources to be used than is needed.
Acknowledgements
This issue was discovered by Found by AISLE in partnership with Red Hat.
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