CVE-2026-43304

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.

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.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.

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.