CVE-2025-68792: 
Linux Kernel vulnerability analysis and mitigation

CVE-2025-68792 is a memory corruption vulnerability in the Linux kernel's TPM2 session handling code (tpm2-sessions), caused by out-of-range array indexing in the name_size function. The function directly indexes memory using TPM_ALG_ID values without any bounds checking, which can lead to memory corruption. It was published on January 13, 2026, and affects Linux kernel versions from commit 1085b8276bb4 up to (but not including) the patched commits. No CVSS score has been assigned by NVD at this time; the ENISA base score is listed as 0.0, and the EPSS score is approximately 0.018% (Feedly, CVE Record).

The root cause is improper input validation (CWE not formally assigned by NVD) in the name_size function within the Linux kernel's tpm2-sessions subsystem. The function uses a TPM_ALG_ID value as a direct array index without validating that it falls within the expected range, enabling out-of-bounds memory access. The fix addresses this by restricting processing to known algorithm values and returning -EINVAL for unrecognized ones; additionally, tpm_buf_append_name and tpm_buf_fill_hmac_session were made fallible so errors are caught before generating spurious TPM traffic, and authorization sessions are now terminated on failure to prevent corrupted session state (Feedly, kernel.org patch 1, kernel.org patch 2).

Successful exploitation of this vulnerability could result in kernel memory corruption, potentially leading to system instability, denial of service (kernel panic/crash), or, in a worst-case scenario, privilege escalation or arbitrary code execution in kernel context. The affected component interacts with TPM2 hardware security modules, meaning exploitation could also undermine the integrity of TPM-based security operations such as secure boot, key storage, and attestation. The scope is limited to systems with TPM2 hardware and a vulnerable kernel version (Feedly).

The vulnerability is fixed in Linux kernel stable commits 04a3aa6e8c5f878cc51a8a1c90b6d3c54079bc43, 6e9722e9a7bfe1bbad649937c811076acf86e1fd, and 47e676ce4d68f461dfcab906f6aeb254f7276deb, with patches included in kernel version 6.18.3 and 6.19-rc1 (Feedly). Downstream distributions including Ubuntu (USN-8177-1, USN-8177-2, USN-8183-1, USN-8183-2, USN-8245-1, USN-8257-1), Debian (linux-signed-amd64 6.12.69+1), and Oracle Enterprise Linux have released updated kernel packages (Ubuntu USN-8177-1, Ubuntu USN-8183-1). Administrators should update to the latest patched kernel version provided by their distribution as the primary remediation; no configuration-based workaround is available.