CVE-2026-43304
Description
A flaw was found in the libceph component of the Linux kernel. This vulnerability occurs when the kernel processes authentication keys, specifically in the process_auth_done() function, where it fails to properly enforce a maximum length for key material. An attacker could exploit this by providing an overly long key, potentially leading to a buffer overflow. This could result in a denial of service (DoS) or other unpredictable system behavior.
Statement
libceph decoded authentication key material without enforcing the maximum key length expected by the fixed-size session key buffer used in process_auth_done(). A malicious or compromised Ceph monitor endpoint, or an attacker able to tamper with monitor authentication traffic, may provide oversized key material and trigger kernel memory corruption in the client auth path. For the CVSS the PR:N is used because no privileges are required on the victim system once the attacker can influence the remote Ceph auth endpoint. The issue is network reachable in Ceph deployments where monitor traffic is exposed to the attacker, although practical exploitation usually requires access to the storage cluster network or control of a trusted monitor. Impact in most cases is remote denial of service via kernel crash only, and only in worst case think of potential confidentiality and integrity impact.
Mitigation
Mitigation for this issue is either not available or the currently available options don't meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.
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 | 7 | N/A | 9.8 |
| Attack Vector | Network | N/A | Network |
| Attack Complexity | High | N/A | Low |
| Privileges Required | None | N/A | None |
| User Interaction | None | N/A | None |
| Scope | Unchanged | N/A | Unchanged |
| Confidentiality | Low | N/A | High |
| Integrity Impact | Low | N/A | High |
| Availability Impact | High | N/A | High |
Vector
Red Hat: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:H
cve.org: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Understanding the Weakness (CWE)
Other,Integrity,Availability
Technical Impact: Varies by Context; DoS: Resource Consumption (CPU); Modify Memory; Read Memory
When the quantity is not properly validated, then attackers can specify malicious quantities to cause excessive resource allocation, trigger unexpected failures, enable buffer overflows, etc.
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