CVE-2026-80707

A flaw was found in the Linux kernel's J1939 CAN bus transport module. When a new session's receive buffer is allocated, it is not properly initialized, which can leave residual data from previous memory usage. A local attacker could potentially exploit this to read sensitive information from the kernel's memory.

A Moderate information disclosure flaw was found in the Linux kernel's J1939 CAN bus transport module (net/can/j1939/transport.c), affecting the kernel and kernel-rt packages in Red Hat Enterprise Linux 9 and 10 and the kernel packages in Red Hat In-Vehicle OS 2. The receive buffer allocated in j1939_session_fresh_new() is not zero-initialized, so residual data from previous kernel memory use can remain in the session's socket buffer. A local attacker with access to the J1939 receive path could potentially exploit this to read sensitive information from the kernel's memory. Red Hat Enterprise Linux 6, 7, and 8 are not affected because the vulnerable code is not present in those releases. For the affected products, the fix has been deferred to a future update; because this is a moderate-severity information disclosure with limited practical exposure, the residual risk is limited to possible disclosure of residual kernel heap contents through the J1939 transport receive path, with no evidence of impact on integrity, availability, or privilege escalation. The upstream CVE record assigns a higher severity (CVSS 3.1 score 7.5, network attack vector) than Red Hat's rating of Moderate (CVSS 3.1 score 5.5, local attack vector) because exploitation requires local access to the system's CAN/J1939 interface rather than remote network access.

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 do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.